經常使用模塊html
模塊,用一砣代碼實現了某個功能的代碼集合。node
相似於函數式編程和麪向過程編程,函數式編程則完成一個功能,其餘代碼用來調用便可,提供了代碼的重用性和代碼間的耦合。而對於一個複雜的功能來,可能須要多個函數才能完成(函數又能夠在不一樣的.py文件中),n個 .py 文件組成的代碼集合就稱爲模塊。python
如:os 是系統相關的模塊;file是文件操做相關的模塊mysql
模塊分爲三種:git
自定義模塊
內置標準模塊(又稱標準庫)
開源模塊
自定義模塊 和開源模塊的使用參考 http://www.cnblogs.com/wupeiqi/articles/4963027.html 程序員
一、定義模塊正則表達式
情景一:算法
情景二:sql
情景三:shell
自定義模塊案例:
handle.py
#!/usr/bin/env python # -*- coding:utf-8 -*- # handle.py from s12day5.dj.backend.db.sql_api import select def home(): print("Welcome to home page") data = select("user", "ddd") print(data)
sql_api.py
#!/usr/bin/env python # -*- coding:utf-8 -*- # sql_api.py from s12day5.dj.config import settings def auth(settings): if settings.DATADASE["user"] == "root" and settings.DATADASE["password"] == "root": print("db authentication passed!") return True else: print("db login error...") def select(table, column): if auth(settings): user_info = { "001": ["alex", 23, "engineer"], "002": ["alex02", 33, "engineer"], "003": ["alex03", 43, "engineer"], } return user_info
settings.py
#!/usr/bin/env python # -*- coding:utf-8 -*- # settings.py DATADASE = { "engine":"mysql", "host":"localhost", "user":"root", "password":"root"}
user.py
#!/usr/bin/env python # -*- coding:utf-8 -*- # user.py from s12day5.dj.backend.logic import handle handle.home()
user.py執行結果:
Welcome to home page db authentication passed! {'001': ['alex', 23, 'engineer'], '002': ['alex02', 33, 'engineer'], '003': ['alex03', 43, 'engineer']}
二、導入模塊
Python之因此應用愈來愈普遍,在必定程度上也依賴於其爲程序員提供了大量的模塊以供使用,若是想要使用模塊,則須要導入。導入模塊有一下幾種方法:
import module from module.xx.xx import xx from module.xx.xx import xx as rename from module.xx.xx import *
導入模塊其實就是告訴Python解釋器去解釋那個py文件
那麼問題來了,導入模塊時是根據那個路徑做爲基準來進行的呢?即:sys.path
import sys print sys.path 結果: ['/Users/wupeiqi/PycharmProjects/calculator/p1/pp1', '/usr/local/lib/python2.7/site-packages/setuptools-15.2-py2.7.egg', '/usr/local/lib/python2.7/site-packages/distribute-0.6.28-py2.7.egg', '/usr/local/lib/python2.7/site-packages/MySQL_python-1.2.4b4-py2.7-macosx-10.10-x86_64.egg', '/usr/local/lib/python2.7/site-packages/xlutils-1.7.1-py2.7.egg', '/usr/local/lib/python2.7/site-packages/xlwt-1.0.0-py2.7.egg', '/usr/local/lib/python2.7/site-packages/xlrd-0.9.3-py2.7.egg', '/usr/local/lib/python2.7/site-packages/tornado-4.1-py2.7-macosx-10.10-x86_64.egg', '/usr/local/lib/python2.7/site-packages/backports.ssl_match_hostname-3.4.0.2-py2.7.egg', '/usr/local/lib/python2.7/site-packages/certifi-2015.4.28-py2.7.egg', '/usr/local/lib/python2.7/site-packages/pyOpenSSL-0.15.1-py2.7.egg', '/usr/local/lib/python2.7/site-packages/six-1.9.0-py2.7.egg', '/usr/local/lib/python2.7/site-packages/cryptography-0.9.1-py2.7-macosx-10.10-x86_64.egg', '/usr/local/lib/python2.7/site-packages/cffi-1.1.1-py2.7-macosx-10.10-x86_64.egg', '/usr/local/lib/python2.7/site-packages/ipaddress-1.0.7-py2.7.egg', '/usr/local/lib/python2.7/site-packages/enum34-1.0.4-py2.7.egg', '/usr/local/lib/python2.7/site-packages/pyasn1-0.1.7-py2.7.egg', '/usr/local/lib/python2.7/site-packages/idna-2.0-py2.7.egg', '/usr/local/lib/python2.7/site-packages/pycparser-2.13-py2.7.egg', '/usr/local/lib/python2.7/site-packages/Django-1.7.8-py2.7.egg', '/usr/local/lib/python2.7/site-packages/paramiko-1.10.1-py2.7.egg', '/usr/local/lib/python2.7/site-packages/gevent-1.0.2-py2.7-macosx-10.10-x86_64.egg', '/usr/local/lib/python2.7/site-packages/greenlet-0.4.7-py2.7-macosx-10.10-x86_64.egg', '/Users/wupeiqi/PycharmProjects/calculator', '/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python27.zip', '/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7', '/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-darwin', '/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac', '/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac/lib-scriptpackages', '/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk', '/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-old', '/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/site-packages', '/Library/Python/2.7/site-packages']
若是sys.path路徑列表沒有你想要的路徑,能夠經過 sys.path.append('路徑') 添加。
經過os模塊能夠獲取各類目錄,例如:
import sys import os pre_path = os.path.abspath('../') sys.path.append(pre_path)
1、下載安裝
下載安裝有兩種方式:
yum pip apt-get ...
下載源碼 解壓源碼 進入目錄 編譯源碼 python setup.py build 安裝源碼 python setup.py install
注:在使用源碼安裝時,須要使用到gcc編譯和python開發環境,因此,須要先執行:
yum install gcc yum install python-devel 或 apt-get python-dev
安裝成功後,模塊會自動安裝到 sys.path 中的某個目錄中,如:
/usr/lib/python2.7/site-packages/
2、導入模塊
同自定義模塊中導入的方式
3、模塊 paramiko
paramiko是一個用於作遠程控制的模塊,使用該模塊能夠對遠程服務器進行命令或文件操做,值得一說的是,fabric和ansible內部的遠程管理就是使用的paramiko來現實。
一、下載安裝
pip3 install paramiko
pip在pycharm安裝目錄/Scripts下,如:D:\ProgramData\Anaconda3\Scripts\pip.exe
或
# pycrypto,因爲 paramiko 模塊內部依賴pycrypto,因此先下載安裝pycrypto # 下載安裝 pycrypto wget http://files.cnblogs.com/files/wupeiqi/pycrypto-2.6.1.tar.gz tar -xvf pycrypto-2.6.1.tar.gz cd pycrypto-2.6.1 python setup.py build python setup.py install # 進入python環境,導入Crypto檢查是否安裝成功 # 下載安裝 paramiko wget http://files.cnblogs.com/files/wupeiqi/paramiko-1.10.1.tar.gz tar -xvf paramiko-1.10.1.tar.gz cd paramiko-1.10.1 python setup.py build python setup.py install # 進入python環境,導入paramiko檢查是否安裝成功
#!/usr/bin/env python #coding:utf-8 import paramiko ssh = paramiko.SSHClient() ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy()) ssh.connect('192.168.1.108', 22, 'alex', '123') stdin, stdout, stderr = ssh.exec_command('df') print stdout.read() ssh.close(); 執行命令 - 經過用戶名和密碼鏈接服務器
import paramiko private_key_path = '/home/auto/.ssh/id_rsa' key = paramiko.RSAKey.from_private_key_file(private_key_path) ssh = paramiko.SSHClient() ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy()) ssh.connect('主機名 ', 端口, '用戶名', key) stdin, stdout, stderr = ssh.exec_command('df') print stdout.read() ssh.close() 執行命令 - 過密鑰連接服務器
import os,sys import paramiko t = paramiko.Transport(('182.92.219.86',22)) t.connect(username='wupeiqi',password='123') sftp = paramiko.SFTPClient.from_transport(t) sftp.put('/tmp/test.py','/tmp/test.py') t.close() import os,sys import paramiko t = paramiko.Transport(('182.92.219.86',22)) t.connect(username='wupeiqi',password='123') sftp = paramiko.SFTPClient.from_transport(t) sftp.get('/tmp/test.py','/tmp/test2.py') t.close() 上傳或者下載文件 - 經過用戶名和密碼
import paramiko pravie_key_path = '/home/auto/.ssh/id_rsa' key = paramiko.RSAKey.from_private_key_file(pravie_key_path) t = paramiko.Transport(('182.92.219.86',22)) t.connect(username='wupeiqi',pkey=key) sftp = paramiko.SFTPClient.from_transport(t) sftp.put('/tmp/test3.py','/tmp/test3.py') t.close() import paramiko pravie_key_path = '/home/auto/.ssh/id_rsa' key = paramiko.RSAKey.from_private_key_file(pravie_key_path) t = paramiko.Transport(('182.92.219.86',22)) t.connect(username='wupeiqi',pkey=key) sftp = paramiko.SFTPClient.from_transport(t) sftp.get('/tmp/test3.py','/tmp/test4.py') t.close() 上傳或下載文件 - 經過密鑰
#_*_coding:utf-8_*_ __author__ = 'Alex Li' import time # print(time.clock()) #返回處理器時間,3.3開始已廢棄 , 改爲了time.process_time()測量處理器運算時間,不包括sleep時間,不穩定,mac上測不出來 # print(time.altzone) #返回與utc時間的時間差,以秒計算\ # print(time.asctime()) #返回時間格式"Fri Aug 19 11:14:16 2016", # print(time.localtime()) #返回本地時間 的struct time對象格式 # print(time.gmtime(time.time()-800000)) #返回utc時間的struc時間對象格式 # print(time.asctime(time.localtime())) #返回時間格式"Fri Aug 19 11:14:16 2016", #print(time.ctime()) #返回Fri Aug 19 12:38:29 2016 格式, 同上 # 日期字符串 轉成 時間戳 # string_2_struct = time.strptime("2016/05/22","%Y/%m/%d") #將 日期字符串 轉成 struct時間對象格式 # print(string_2_struct) # # # struct_2_stamp = time.mktime(string_2_struct) #將struct時間對象轉成時間戳 # print(struct_2_stamp) #將時間戳轉爲字符串格式 # print(time.gmtime(time.time()-86640)) #將utc時間戳轉換成struct_time格式 # print(time.strftime("%Y-%m-%d %H:%M:%S",time.gmtime()) ) #將utc struct_time格式轉成指定的字符串格式 #時間加減 import datetime # print(datetime.datetime.now()) #返回 2016-08-19 12:47:03.941925 #print(datetime.date.fromtimestamp(time.time()) ) # 時間戳直接轉成日期格式 2016-08-19 # print(datetime.datetime.now() ) # print(datetime.datetime.now() + datetime.timedelta(3)) #當前時間+3天 # print(datetime.datetime.now() + datetime.timedelta(-3)) #當前時間-3天 # print(datetime.datetime.now() + datetime.timedelta(hours=3)) #當前時間+3小時 # print(datetime.datetime.now() + datetime.timedelta(minutes=30)) #當前時間+30分 # # c_time = datetime.datetime.now() # print(c_time.replace(minute=3,hour=2)) #時間替換
Directive | Meaning | Notes |
---|---|---|
%a |
Locale’s abbreviated weekday name. | |
%A |
Locale’s full weekday name. | |
%b |
Locale’s abbreviated month name. | |
%B |
Locale’s full month name. | |
%c |
Locale’s appropriate date and time representation. | |
%d |
Day of the month as a decimal number [01,31]. | |
%H |
Hour (24-hour clock) as a decimal number [00,23]. | |
%I |
Hour (12-hour clock) as a decimal number [01,12]. | |
%j |
Day of the year as a decimal number [001,366]. | |
%m |
Month as a decimal number [01,12]. | |
%M |
Minute as a decimal number [00,59]. | |
%p |
Locale’s equivalent of either AM or PM. | (1) |
%S |
Second as a decimal number [00,61]. | (2) |
%U |
Week number of the year (Sunday as the first day of the week) as a decimal number [00,53]. All days in a new year preceding the first Sunday are considered to be in week 0. | (3) |
%w |
Weekday as a decimal number [0(Sunday),6]. | |
%W |
Week number of the year (Monday as the first day of the week) as a decimal number [00,53]. All days in a new year preceding the first Monday are considered to be in week 0. | (3) |
%x |
Locale’s appropriate date representation. | |
%X |
Locale’s appropriate time representation. | |
%y |
Year without century as a decimal number [00,99]. | |
%Y |
Year with century as a decimal number. | |
%z |
Time zone offset indicating a positive or negative time difference from UTC/GMT of the form +HHMM or -HHMM, where H represents decimal hour digits and M represents decimal minute digits [-23:59, +23:59]. | |
%Z |
Time zone name (no characters if no time zone exists). | |
%% |
A literal '%' character. |
mport random print random.random() print random.randint(1,2) print random.randrange(1,10)
生成隨機驗證碼
import random checkcode = '' for i in range(4): current = random.randrange(0,4) if current != i: temp = chr(random.randint(65,90)) else: temp = random.randint(0,9) checkcode += str(temp) print checkcode
提供對操做系統進行調用的接口
os.getcwd() 獲取當前工做目錄,即當前python腳本工做的目錄路徑 os.chdir("dirname") 改變當前腳本工做目錄;至關於shell下cd os.curdir 返回當前目錄: ('.') os.pardir 獲取當前目錄的父目錄字符串名:('..') os.makedirs('dirname1/dirname2') 可生成多層遞歸目錄 os.removedirs('dirname1') 若目錄爲空,則刪除,並遞歸到上一級目錄,如若也爲空,則刪除,依此類推 os.mkdir('dirname') 生成單級目錄;至關於shell中mkdir dirname os.rmdir('dirname') 刪除單級空目錄,若目錄不爲空則沒法刪除,報錯;至關於shell中rmdir dirname os.listdir('dirname') 列出指定目錄下的全部文件和子目錄,包括隱藏文件,並以列表方式打印 os.remove() 刪除一個文件 os.rename("oldname","newname") 重命名文件/目錄 os.stat('path/filename') 獲取文件/目錄信息 os.sep 輸出操做系統特定的路徑分隔符,win下爲"\\",Linux下爲"/" os.linesep 輸出當前平臺使用的行終止符,win下爲"\t\n",Linux下爲"\n" os.pathsep 輸出用於分割文件路徑的字符串 os.name 輸出字符串指示當前使用平臺。win->'nt'; Linux->'posix' os.system("bash command") 運行shell命令,直接顯示 os.environ 獲取系統環境變量 os.path.abspath(path) 返回path規範化的絕對路徑 os.path.split(path) 將path分割成目錄和文件名二元組返回 os.path.dirname(path) 返回path的目錄。其實就是os.path.split(path)的第一個元素 os.path.basename(path) 返回path最後的文件名。如何path以/或\結尾,那麼就會返回空值。即os.path.split(path)的第二個元素 os.path.exists(path) 若是path存在,返回True;若是path不存在,返回False os.path.isabs(path) 若是path是絕對路徑,返回True os.path.isfile(path) 若是path是一個存在的文件,返回True。不然返回False os.path.isdir(path) 若是path是一個存在的目錄,則返回True。不然返回False os.path.join(path1[, path2[, ...]]) 將多個路徑組合後返回,第一個絕對路徑以前的參數將被忽略 os.path.getatime(path) 返回path所指向的文件或者目錄的最後存取時間 os.path.getmtime(path) 返回path所指向的文件或者目錄的最後修改時間
更多猛擊這裏
sys.argv 命令行參數List,第一個元素是程序自己路徑 sys.exit(n) 退出程序,正常退出時exit(0) sys.version 獲取Python解釋程序的版本信息 sys.maxint 最大的Int值 sys.path 返回模塊的搜索路徑,初始化時使用PYTHONPATH環境變量的值 sys.platform 返回操做系統平臺名稱 sys.stdout.write('please:') val = sys.stdin.readline()[:-1]
直接參考 http://www.cnblogs.com/wupeiqi/articles/4963027.html
高級的 文件、文件夾、壓縮包 處理模塊
shutil.copyfileobj(fsrc, fdst[, length])
將文件內容拷貝到另外一個文件中,能夠部份內容
def copyfileobj(fsrc, fdst, length=16*1024): """copy data from file-like object fsrc to file-like object fdst""" while 1: buf = fsrc.read(length) if not buf: break fdst.write(buf)
shutil.copyfile(src, dst)
拷貝文件
def copyfile(src, dst): """Copy data from src to dst""" if _samefile(src, dst): raise Error("`%s` and `%s` are the same file" % (src, dst)) for fn in [src, dst]: try: st = os.stat(fn) except OSError: # File most likely does not exist pass else: # XXX What about other special files? (sockets, devices...) if stat.S_ISFIFO(st.st_mode): raise SpecialFileError("`%s` is a named pipe" % fn) with open(src, 'rb') as fsrc: with open(dst, 'wb') as fdst: copyfileobj(fsrc, fdst)
shutil.copymode(src, dst)
僅拷貝權限。內容、組、用戶均不變
def copymode(src, dst): """Copy mode bits from src to dst""" if hasattr(os, 'chmod'): st = os.stat(src) mode = stat.S_IMODE(st.st_mode) os.chmod(dst, mode)
shutil.copystat(src, dst)
拷貝狀態的信息,包括:mode bits, atime, mtime, flags
def copystat(src, dst): """Copy all stat info (mode bits, atime, mtime, flags) from src to dst""" st = os.stat(src) mode = stat.S_IMODE(st.st_mode) if hasattr(os, 'utime'): os.utime(dst, (st.st_atime, st.st_mtime)) if hasattr(os, 'chmod'): os.chmod(dst, mode) if hasattr(os, 'chflags') and hasattr(st, 'st_flags'): try: os.chflags(dst, st.st_flags) except OSError, why: for err in 'EOPNOTSUPP', 'ENOTSUP': if hasattr(errno, err) and why.errno == getattr(errno, err): break else: raise
shutil.copy(src, dst)
拷貝文件和權限
def copy(src, dst): """Copy data and mode bits ("cp src dst"). The destination may be a directory. """ if os.path.isdir(dst): dst = os.path.join(dst, os.path.basename(src)) copyfile(src, dst) copymode(src, dst)
shutil.copy2(src, dst)
拷貝文件和狀態信息
def copy2(src, dst): """Copy data and all stat info ("cp -p src dst"). The destination may be a directory. """ if os.path.isdir(dst): dst = os.path.join(dst, os.path.basename(src)) copyfile(src, dst) copystat(src, dst)
shutil.ignore_patterns(*patterns)
shutil.copytree(src, dst, symlinks=False, ignore=None)
遞歸的去拷貝文件
例如:copytree(source, destination, ignore=ignore_patterns('*.pyc', 'tmp*'))
def ignore_patterns(*patterns): """Function that can be used as copytree() ignore parameter. Patterns is a sequence of glob-style patterns that are used to exclude files""" def _ignore_patterns(path, names): ignored_names = [] for pattern in patterns: ignored_names.extend(fnmatch.filter(names, pattern)) return set(ignored_names) return _ignore_patterns def copytree(src, dst, symlinks=False, ignore=None): """Recursively copy a directory tree using copy2(). The destination directory must not already exist. If exception(s) occur, an Error is raised with a list of reasons. If the optional symlinks flag is true, symbolic links in the source tree result in symbolic links in the destination tree; if it is false, the contents of the files pointed to by symbolic links are copied. The optional ignore argument is a callable. If given, it is called with the `src` parameter, which is the directory being visited by copytree(), and `names` which is the list of `src` contents, as returned by os.listdir(): callable(src, names) -> ignored_names Since copytree() is called recursively, the callable will be called once for each directory that is copied. It returns a list of names relative to the `src` directory that should not be copied. XXX Consider this example code rather than the ultimate tool. """ names = os.listdir(src) if ignore is not None: ignored_names = ignore(src, names) else: ignored_names = set() os.makedirs(dst) errors = [] for name in names: if name in ignored_names: continue srcname = os.path.join(src, name) dstname = os.path.join(dst, name) try: if symlinks and os.path.islink(srcname): linkto = os.readlink(srcname) os.symlink(linkto, dstname) elif os.path.isdir(srcname): copytree(srcname, dstname, symlinks, ignore) else: # Will raise a SpecialFileError for unsupported file types copy2(srcname, dstname) # catch the Error from the recursive copytree so that we can # continue with other files except Error, err: errors.extend(err.args[0]) except EnvironmentError, why: errors.append((srcname, dstname, str(why))) try: copystat(src, dst) except OSError, why: if WindowsError is not None and isinstance(why, WindowsError): # Copying file access times may fail on Windows pass else: errors.append((src, dst, str(why))) if errors: raise Error, errors
shutil.rmtree(path[, ignore_errors[, onerror]])
遞歸的去刪除文件
def rmtree(path, ignore_errors=False, onerror=None): """Recursively delete a directory tree. If ignore_errors is set, errors are ignored; otherwise, if onerror is set, it is called to handle the error with arguments (func, path, exc_info) where func is os.listdir, os.remove, or os.rmdir; path is the argument to that function that caused it to fail; and exc_info is a tuple returned by sys.exc_info(). If ignore_errors is false and onerror is None, an exception is raised. """ if ignore_errors: def onerror(*args): pass elif onerror is None: def onerror(*args): raise try: if os.path.islink(path): # symlinks to directories are forbidden, see bug #1669 raise OSError("Cannot call rmtree on a symbolic link") except OSError: onerror(os.path.islink, path, sys.exc_info()) # can't continue even if onerror hook returns return names = [] try: names = os.listdir(path) except os.error, err: onerror(os.listdir, path, sys.exc_info()) for name in names: fullname = os.path.join(path, name) try: mode = os.lstat(fullname).st_mode except os.error: mode = 0 if stat.S_ISDIR(mode): rmtree(fullname, ignore_errors, onerror) else: try: os.remove(fullname) except os.error, err: onerror(os.remove, fullname, sys.exc_info()) try: os.rmdir(path) except os.error: onerror(os.rmdir, path, sys.exc_info())
shutil.move(src, dst)
遞歸的去移動文件
def move(src, dst): """Recursively move a file or directory to another location. This is similar to the Unix "mv" command. If the destination is a directory or a symlink to a directory, the source is moved inside the directory. The destination path must not already exist. If the destination already exists but is not a directory, it may be overwritten depending on os.rename() semantics. If the destination is on our current filesystem, then rename() is used. Otherwise, src is copied to the destination and then removed. A lot more could be done here... A look at a mv.c shows a lot of the issues this implementation glosses over. """ real_dst = dst if os.path.isdir(dst): if _samefile(src, dst): # We might be on a case insensitive filesystem, # perform the rename anyway. os.rename(src, dst) return real_dst = os.path.join(dst, _basename(src)) if os.path.exists(real_dst): raise Error, "Destination path '%s' already exists" % real_dst try: os.rename(src, real_dst) except OSError: if os.path.isdir(src): if _destinsrc(src, dst): raise Error, "Cannot move a directory '%s' into itself '%s'." % (src, dst) copytree(src, real_dst, symlinks=True) rmtree(src) else: copy2(src, real_dst) os.unlink(src)
shutil.make_archive(base_name, format,...)
建立壓縮包並返回文件路徑,例如:zip、tar
#將 /Users/wupeiqi/Downloads/test 下的文件打包放置當前程序目錄 import shutil ret = shutil.make_archive("wwwwwwwwww", 'gztar', root_dir='/Users/wupeiqi/Downloads/test') #將 /Users/wupeiqi/Downloads/test 下的文件打包放置 /Users/wupeiqi/目錄 import shutil ret = shutil.make_archive("/Users/wupeiqi/wwwwwwwwww", 'gztar', root_dir='/Users/wupeiqi/Downloads/test')
def make_archive(base_name, format, root_dir=None, base_dir=None, verbose=0, dry_run=0, owner=None, group=None, logger=None): """Create an archive file (eg. zip or tar). 'base_name' is the name of the file to create, minus any format-specific extension; 'format' is the archive format: one of "zip", "tar", "bztar" or "gztar". 'root_dir' is a directory that will be the root directory of the archive; ie. we typically chdir into 'root_dir' before creating the archive. 'base_dir' is the directory where we start archiving from; ie. 'base_dir' will be the common prefix of all files and directories in the archive. 'root_dir' and 'base_dir' both default to the current directory. Returns the name of the archive file. 'owner' and 'group' are used when creating a tar archive. By default, uses the current owner and group. """ save_cwd = os.getcwd() if root_dir is not None: if logger is not None: logger.debug("changing into '%s'", root_dir) base_name = os.path.abspath(base_name) if not dry_run: os.chdir(root_dir) if base_dir is None: base_dir = os.curdir kwargs = {'dry_run': dry_run, 'logger': logger} try: format_info = _ARCHIVE_FORMATS[format] except KeyError: raise ValueError, "unknown archive format '%s'" % format func = format_info[0] for arg, val in format_info[1]: kwargs[arg] = val if format != 'zip': kwargs['owner'] = owner kwargs['group'] = group try: filename = func(base_name, base_dir, **kwargs) finally: if root_dir is not None: if logger is not None: logger.debug("changing back to '%s'", save_cwd) os.chdir(save_cwd) return filename
shutil 對壓縮包的處理是調用 ZipFile 和 TarFile 兩個模塊來進行的,詳細:
import zipfile # 壓縮 z = zipfile.ZipFile('laxi.zip', 'w') z.write('a.log') z.write('data.data') z.close() # 解壓 z = zipfile.ZipFile('laxi.zip', 'r') z.extractall() z.close() zipfile 壓縮解壓
import tarfile # 壓縮 tar = tarfile.open('your.tar','w') tar.add('/Users/wupeiqi/PycharmProjects/bbs2.zip', arcname='bbs2.zip') tar.add('/Users/wupeiqi/PycharmProjects/cmdb.zip', arcname='cmdb.zip') tar.close() # 解壓 tar = tarfile.open('your.tar','r') tar.extractall() # 可設置解壓地址 tar.close() tarfile 壓縮解壓
class ZipFile(object): """ Class with methods to open, read, write, close, list zip files. z = ZipFile(file, mode="r", compression=ZIP_STORED, allowZip64=False) file: Either the path to the file, or a file-like object. If it is a path, the file will be opened and closed by ZipFile. mode: The mode can be either read "r", write "w" or append "a". compression: ZIP_STORED (no compression) or ZIP_DEFLATED (requires zlib). allowZip64: if True ZipFile will create files with ZIP64 extensions when needed, otherwise it will raise an exception when this would be necessary. """ fp = None # Set here since __del__ checks it def __init__(self, file, mode="r", compression=ZIP_STORED, allowZip64=False): """Open the ZIP file with mode read "r", write "w" or append "a".""" if mode not in ("r", "w", "a"): raise RuntimeError('ZipFile() requires mode "r", "w", or "a"') if compression == ZIP_STORED: pass elif compression == ZIP_DEFLATED: if not zlib: raise RuntimeError,\ "Compression requires the (missing) zlib module" else: raise RuntimeError, "That compression method is not supported" self._allowZip64 = allowZip64 self._didModify = False self.debug = 0 # Level of printing: 0 through 3 self.NameToInfo = {} # Find file info given name self.filelist = [] # List of ZipInfo instances for archive self.compression = compression # Method of compression self.mode = key = mode.replace('b', '')[0] self.pwd = None self._comment = '' # Check if we were passed a file-like object if isinstance(file, basestring): self._filePassed = 0 self.filename = file modeDict = {'r' : 'rb', 'w': 'wb', 'a' : 'r+b'} try: self.fp = open(file, modeDict[mode]) except IOError: if mode == 'a': mode = key = 'w' self.fp = open(file, modeDict[mode]) else: raise else: self._filePassed = 1 self.fp = file self.filename = getattr(file, 'name', None) try: if key == 'r': self._RealGetContents() elif key == 'w': # set the modified flag so central directory gets written # even if no files are added to the archive self._didModify = True elif key == 'a': try: # See if file is a zip file self._RealGetContents() # seek to start of directory and overwrite self.fp.seek(self.start_dir, 0) except BadZipfile: # file is not a zip file, just append self.fp.seek(0, 2) # set the modified flag so central directory gets written # even if no files are added to the archive self._didModify = True else: raise RuntimeError('Mode must be "r", "w" or "a"') except: fp = self.fp self.fp = None if not self._filePassed: fp.close() raise def __enter__(self): return self def __exit__(self, type, value, traceback): self.close() def _RealGetContents(self): """Read in the table of contents for the ZIP file.""" fp = self.fp try: endrec = _EndRecData(fp) except IOError: raise BadZipfile("File is not a zip file") if not endrec: raise BadZipfile, "File is not a zip file" if self.debug > 1: print endrec size_cd = endrec[_ECD_SIZE] # bytes in central directory offset_cd = endrec[_ECD_OFFSET] # offset of central directory self._comment = endrec[_ECD_COMMENT] # archive comment # "concat" is zero, unless zip was concatenated to another file concat = endrec[_ECD_LOCATION] - size_cd - offset_cd if endrec[_ECD_SIGNATURE] == stringEndArchive64: # If Zip64 extension structures are present, account for them concat -= (sizeEndCentDir64 + sizeEndCentDir64Locator) if self.debug > 2: inferred = concat + offset_cd print "given, inferred, offset", offset_cd, inferred, concat # self.start_dir: Position of start of central directory self.start_dir = offset_cd + concat fp.seek(self.start_dir, 0) data = fp.read(size_cd) fp = cStringIO.StringIO(data) total = 0 while total < size_cd: centdir = fp.read(sizeCentralDir) if len(centdir) != sizeCentralDir: raise BadZipfile("Truncated central directory") centdir = struct.unpack(structCentralDir, centdir) if centdir[_CD_SIGNATURE] != stringCentralDir: raise BadZipfile("Bad magic number for central directory") if self.debug > 2: print centdir filename = fp.read(centdir[_CD_FILENAME_LENGTH]) # Create ZipInfo instance to store file information x = ZipInfo(filename) x.extra = fp.read(centdir[_CD_EXTRA_FIELD_LENGTH]) x.comment = fp.read(centdir[_CD_COMMENT_LENGTH]) x.header_offset = centdir[_CD_LOCAL_HEADER_OFFSET] (x.create_version, x.create_system, x.extract_version, x.reserved, x.flag_bits, x.compress_type, t, d, x.CRC, x.compress_size, x.file_size) = centdir[1:12] x.volume, x.internal_attr, x.external_attr = centdir[15:18] # Convert date/time code to (year, month, day, hour, min, sec) x._raw_time = t x.date_time = ( (d>>9)+1980, (d>>5)&0xF, d&0x1F, t>>11, (t>>5)&0x3F, (t&0x1F) * 2 ) x._decodeExtra() x.header_offset = x.header_offset + concat x.filename = x._decodeFilename() self.filelist.append(x) self.NameToInfo[x.filename] = x # update total bytes read from central directory total = (total + sizeCentralDir + centdir[_CD_FILENAME_LENGTH] + centdir[_CD_EXTRA_FIELD_LENGTH] + centdir[_CD_COMMENT_LENGTH]) if self.debug > 2: print "total", total def namelist(self): """Return a list of file names in the archive.""" l = [] for data in self.filelist: l.append(data.filename) return l def infolist(self): """Return a list of class ZipInfo instances for files in the archive.""" return self.filelist def printdir(self): """Print a table of contents for the zip file.""" print "%-46s %19s %12s" % ("File Name", "Modified ", "Size") for zinfo in self.filelist: date = "%d-%02d-%02d %02d:%02d:%02d" % zinfo.date_time[:6] print "%-46s %s %12d" % (zinfo.filename, date, zinfo.file_size) def testzip(self): """Read all the files and check the CRC.""" chunk_size = 2 ** 20 for zinfo in self.filelist: try: # Read by chunks, to avoid an OverflowError or a # MemoryError with very large embedded files. with self.open(zinfo.filename, "r") as f: while f.read(chunk_size): # Check CRC-32 pass except BadZipfile: return zinfo.filename def getinfo(self, name): """Return the instance of ZipInfo given 'name'.""" info = self.NameToInfo.get(name) if info is None: raise KeyError( 'There is no item named %r in the archive' % name) return info def setpassword(self, pwd): """Set default password for encrypted files.""" self.pwd = pwd @property def comment(self): """The comment text associated with the ZIP file.""" return self._comment @comment.setter def comment(self, comment): # check for valid comment length if len(comment) > ZIP_MAX_COMMENT: import warnings warnings.warn('Archive comment is too long; truncating to %d bytes' % ZIP_MAX_COMMENT, stacklevel=2) comment = comment[:ZIP_MAX_COMMENT] self._comment = comment self._didModify = True def read(self, name, pwd=None): """Return file bytes (as a string) for name.""" return self.open(name, "r", pwd).read() def open(self, name, mode="r", pwd=None): """Return file-like object for 'name'.""" if mode not in ("r", "U", "rU"): raise RuntimeError, 'open() requires mode "r", "U", or "rU"' if not self.fp: raise RuntimeError, \ "Attempt to read ZIP archive that was already closed" # Only open a new file for instances where we were not # given a file object in the constructor if self._filePassed: zef_file = self.fp should_close = False else: zef_file = open(self.filename, 'rb') should_close = True try: # Make sure we have an info object if isinstance(name, ZipInfo): # 'name' is already an info object zinfo = name else: # Get info object for name zinfo = self.getinfo(name) zef_file.seek(zinfo.header_offset, 0) # Skip the file header: fheader = zef_file.read(sizeFileHeader) if len(fheader) != sizeFileHeader: raise BadZipfile("Truncated file header") fheader = struct.unpack(structFileHeader, fheader) if fheader[_FH_SIGNATURE] != stringFileHeader: raise BadZipfile("Bad magic number for file header") fname = zef_file.read(fheader[_FH_FILENAME_LENGTH]) if fheader[_FH_EXTRA_FIELD_LENGTH]: zef_file.read(fheader[_FH_EXTRA_FIELD_LENGTH]) if fname != zinfo.orig_filename: raise BadZipfile, \ 'File name in directory "%s" and header "%s" differ.' % ( zinfo.orig_filename, fname) # check for encrypted flag & handle password is_encrypted = zinfo.flag_bits & 0x1 zd = None if is_encrypted: if not pwd: pwd = self.pwd if not pwd: raise RuntimeError, "File %s is encrypted, " \ "password required for extraction" % name zd = _ZipDecrypter(pwd) # The first 12 bytes in the cypher stream is an encryption header # used to strengthen the algorithm. The first 11 bytes are # completely random, while the 12th contains the MSB of the CRC, # or the MSB of the file time depending on the header type # and is used to check the correctness of the password. bytes = zef_file.read(12) h = map(zd, bytes[0:12]) if zinfo.flag_bits & 0x8: # compare against the file type from extended local headers check_byte = (zinfo._raw_time >> 8) & 0xff else: # compare against the CRC otherwise check_byte = (zinfo.CRC >> 24) & 0xff if ord(h[11]) != check_byte: raise RuntimeError("Bad password for file", name) return ZipExtFile(zef_file, mode, zinfo, zd, close_fileobj=should_close) except: if should_close: zef_file.close() raise def extract(self, member, path=None, pwd=None): """Extract a member from the archive to the current working directory, using its full name. Its file information is extracted as accurately as possible. `member' may be a filename or a ZipInfo object. You can specify a different directory using `path'. """ if not isinstance(member, ZipInfo): member = self.getinfo(member) if path is None: path = os.getcwd() return self._extract_member(member, path, pwd) def extractall(self, path=None, members=None, pwd=None): """Extract all members from the archive to the current working directory. `path' specifies a different directory to extract to. `members' is optional and must be a subset of the list returned by namelist(). """ if members is None: members = self.namelist() for zipinfo in members: self.extract(zipinfo, path, pwd) def _extract_member(self, member, targetpath, pwd): """Extract the ZipInfo object 'member' to a physical file on the path targetpath. """ # build the destination pathname, replacing # forward slashes to platform specific separators. arcname = member.filename.replace('/', os.path.sep) if os.path.altsep: arcname = arcname.replace(os.path.altsep, os.path.sep) # interpret absolute pathname as relative, remove drive letter or # UNC path, redundant separators, "." and ".." components. arcname = os.path.splitdrive(arcname)[1] arcname = os.path.sep.join(x for x in arcname.split(os.path.sep) if x not in ('', os.path.curdir, os.path.pardir)) if os.path.sep == '\\': # filter illegal characters on Windows illegal = ':<>|"?*' if isinstance(arcname, unicode): table = {ord(c): ord('_') for c in illegal} else: table = string.maketrans(illegal, '_' * len(illegal)) arcname = arcname.translate(table) # remove trailing dots arcname = (x.rstrip('.') for x in arcname.split(os.path.sep)) arcname = os.path.sep.join(x for x in arcname if x) targetpath = os.path.join(targetpath, arcname) targetpath = os.path.normpath(targetpath) # Create all upper directories if necessary. upperdirs = os.path.dirname(targetpath) if upperdirs and not os.path.exists(upperdirs): os.makedirs(upperdirs) if member.filename[-1] == '/': if not os.path.isdir(targetpath): os.mkdir(targetpath) return targetpath with self.open(member, pwd=pwd) as source, \ file(targetpath, "wb") as target: shutil.copyfileobj(source, target) return targetpath def _writecheck(self, zinfo): """Check for errors before writing a file to the archive.""" if zinfo.filename in self.NameToInfo: import warnings warnings.warn('Duplicate name: %r' % zinfo.filename, stacklevel=3) if self.mode not in ("w", "a"): raise RuntimeError, 'write() requires mode "w" or "a"' if not self.fp: raise RuntimeError, \ "Attempt to write ZIP archive that was already closed" if zinfo.compress_type == ZIP_DEFLATED and not zlib: raise RuntimeError, \ "Compression requires the (missing) zlib module" if zinfo.compress_type not in (ZIP_STORED, ZIP_DEFLATED): raise RuntimeError, \ "That compression method is not supported" if not self._allowZip64: requires_zip64 = None if len(self.filelist) >= ZIP_FILECOUNT_LIMIT: requires_zip64 = "Files count" elif zinfo.file_size > ZIP64_LIMIT: requires_zip64 = "Filesize" elif zinfo.header_offset > ZIP64_LIMIT: requires_zip64 = "Zipfile size" if requires_zip64: raise LargeZipFile(requires_zip64 + " would require ZIP64 extensions") def write(self, filename, arcname=None, compress_type=None): """Put the bytes from filename into the archive under the name arcname.""" if not self.fp: raise RuntimeError( "Attempt to write to ZIP archive that was already closed") st = os.stat(filename) isdir = stat.S_ISDIR(st.st_mode) mtime = time.localtime(st.st_mtime) date_time = mtime[0:6] # Create ZipInfo instance to store file information if arcname is None: arcname = filename arcname = os.path.normpath(os.path.splitdrive(arcname)[1]) while arcname[0] in (os.sep, os.altsep): arcname = arcname[1:] if isdir: arcname += '/' zinfo = ZipInfo(arcname, date_time) zinfo.external_attr = (st[0] & 0xFFFF) << 16L # Unix attributes if compress_type is None: zinfo.compress_type = self.compression else: zinfo.compress_type = compress_type zinfo.file_size = st.st_size zinfo.flag_bits = 0x00 zinfo.header_offset = self.fp.tell() # Start of header bytes self._writecheck(zinfo) self._didModify = True if isdir: zinfo.file_size = 0 zinfo.compress_size = 0 zinfo.CRC = 0 zinfo.external_attr |= 0x10 # MS-DOS directory flag self.filelist.append(zinfo) self.NameToInfo[zinfo.filename] = zinfo self.fp.write(zinfo.FileHeader(False)) return with open(filename, "rb") as fp: # Must overwrite CRC and sizes with correct data later zinfo.CRC = CRC = 0 zinfo.compress_size = compress_size = 0 # Compressed size can be larger than uncompressed size zip64 = self._allowZip64 and \ zinfo.file_size * 1.05 > ZIP64_LIMIT self.fp.write(zinfo.FileHeader(zip64)) if zinfo.compress_type == ZIP_DEFLATED: cmpr = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION, zlib.DEFLATED, -15) else: cmpr = None file_size = 0 while 1: buf = fp.read(1024 * 8) if not buf: break file_size = file_size + len(buf) CRC = crc32(buf, CRC) & 0xffffffff if cmpr: buf = cmpr.compress(buf) compress_size = compress_size + len(buf) self.fp.write(buf) if cmpr: buf = cmpr.flush() compress_size = compress_size + len(buf) self.fp.write(buf) zinfo.compress_size = compress_size else: zinfo.compress_size = file_size zinfo.CRC = CRC zinfo.file_size = file_size if not zip64 and self._allowZip64: if file_size > ZIP64_LIMIT: raise RuntimeError('File size has increased during compressing') if compress_size > ZIP64_LIMIT: raise RuntimeError('Compressed size larger than uncompressed size') # Seek backwards and write file header (which will now include # correct CRC and file sizes) position = self.fp.tell() # Preserve current position in file self.fp.seek(zinfo.header_offset, 0) self.fp.write(zinfo.FileHeader(zip64)) self.fp.seek(position, 0) self.filelist.append(zinfo) self.NameToInfo[zinfo.filename] = zinfo def writestr(self, zinfo_or_arcname, bytes, compress_type=None): """Write a file into the archive. The contents is the string 'bytes'. 'zinfo_or_arcname' is either a ZipInfo instance or the name of the file in the archive.""" if not isinstance(zinfo_or_arcname, ZipInfo): zinfo = ZipInfo(filename=zinfo_or_arcname, date_time=time.localtime(time.time())[:6]) zinfo.compress_type = self.compression if zinfo.filename[-1] == '/': zinfo.external_attr = 0o40775 << 16 # drwxrwxr-x zinfo.external_attr |= 0x10 # MS-DOS directory flag else: zinfo.external_attr = 0o600 << 16 # ?rw------- else: zinfo = zinfo_or_arcname if not self.fp: raise RuntimeError( "Attempt to write to ZIP archive that was already closed") if compress_type is not None: zinfo.compress_type = compress_type zinfo.file_size = len(bytes) # Uncompressed size zinfo.header_offset = self.fp.tell() # Start of header bytes self._writecheck(zinfo) self._didModify = True zinfo.CRC = crc32(bytes) & 0xffffffff # CRC-32 checksum if zinfo.compress_type == ZIP_DEFLATED: co = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION, zlib.DEFLATED, -15) bytes = co.compress(bytes) + co.flush() zinfo.compress_size = len(bytes) # Compressed size else: zinfo.compress_size = zinfo.file_size zip64 = zinfo.file_size > ZIP64_LIMIT or \ zinfo.compress_size > ZIP64_LIMIT if zip64 and not self._allowZip64: raise LargeZipFile("Filesize would require ZIP64 extensions") self.fp.write(zinfo.FileHeader(zip64)) self.fp.write(bytes) if zinfo.flag_bits & 0x08: # Write CRC and file sizes after the file data fmt = '<LQQ' if zip64 else '<LLL' self.fp.write(struct.pack(fmt, zinfo.CRC, zinfo.compress_size, zinfo.file_size)) self.fp.flush() self.filelist.append(zinfo) self.NameToInfo[zinfo.filename] = zinfo def __del__(self): """Call the "close()" method in case the user forgot.""" self.close() def close(self): """Close the file, and for mode "w" and "a" write the ending records.""" if self.fp is None: return try: if self.mode in ("w", "a") and self._didModify: # write ending records pos1 = self.fp.tell() for zinfo in self.filelist: # write central directory dt = zinfo.date_time dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2] dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2) extra = [] if zinfo.file_size > ZIP64_LIMIT \ or zinfo.compress_size > ZIP64_LIMIT: extra.append(zinfo.file_size) extra.append(zinfo.compress_size) file_size = 0xffffffff compress_size = 0xffffffff else: file_size = zinfo.file_size compress_size = zinfo.compress_size if zinfo.header_offset > ZIP64_LIMIT: extra.append(zinfo.header_offset) header_offset = 0xffffffffL else: header_offset = zinfo.header_offset extra_data = zinfo.extra if extra: # Append a ZIP64 field to the extra's extra_data = struct.pack( '<HH' + 'Q'*len(extra), 1, 8*len(extra), *extra) + extra_data extract_version = max(45, zinfo.extract_version) create_version = max(45, zinfo.create_version) else: extract_version = zinfo.extract_version create_version = zinfo.create_version try: filename, flag_bits = zinfo._encodeFilenameFlags() centdir = struct.pack(structCentralDir, stringCentralDir, create_version, zinfo.create_system, extract_version, zinfo.reserved, flag_bits, zinfo.compress_type, dostime, dosdate, zinfo.CRC, compress_size, file_size, len(filename), len(extra_data), len(zinfo.comment), 0, zinfo.internal_attr, zinfo.external_attr, header_offset) except DeprecationWarning: print >>sys.stderr, (structCentralDir, stringCentralDir, create_version, zinfo.create_system, extract_version, zinfo.reserved, zinfo.flag_bits, zinfo.compress_type, dostime, dosdate, zinfo.CRC, compress_size, file_size, len(zinfo.filename), len(extra_data), len(zinfo.comment), 0, zinfo.internal_attr, zinfo.external_attr, header_offset) raise self.fp.write(centdir) self.fp.write(filename) self.fp.write(extra_data) self.fp.write(zinfo.comment) pos2 = self.fp.tell() # Write end-of-zip-archive record centDirCount = len(self.filelist) centDirSize = pos2 - pos1 centDirOffset = pos1 requires_zip64 = None if centDirCount > ZIP_FILECOUNT_LIMIT: requires_zip64 = "Files count" elif centDirOffset > ZIP64_LIMIT: requires_zip64 = "Central directory offset" elif centDirSize > ZIP64_LIMIT: requires_zip64 = "Central directory size" if requires_zip64: # Need to write the ZIP64 end-of-archive records if not self._allowZip64: raise LargeZipFile(requires_zip64 + " would require ZIP64 extensions") zip64endrec = struct.pack( structEndArchive64, stringEndArchive64, 44, 45, 45, 0, 0, centDirCount, centDirCount, centDirSize, centDirOffset) self.fp.write(zip64endrec) zip64locrec = struct.pack( structEndArchive64Locator, stringEndArchive64Locator, 0, pos2, 1) self.fp.write(zip64locrec) centDirCount = min(centDirCount, 0xFFFF) centDirSize = min(centDirSize, 0xFFFFFFFF) centDirOffset = min(centDirOffset, 0xFFFFFFFF) endrec = struct.pack(structEndArchive, stringEndArchive, 0, 0, centDirCount, centDirCount, centDirSize, centDirOffset, len(self._comment)) self.fp.write(endrec) self.fp.write(self._comment) self.fp.flush() finally: fp = self.fp self.fp = None if not self._filePassed: fp.close() ZipFile
class TarFile(object): """The TarFile Class provides an interface to tar archives. """ debug = 0 # May be set from 0 (no msgs) to 3 (all msgs) dereference = False # If true, add content of linked file to the # tar file, else the link. ignore_zeros = False # If true, skips empty or invalid blocks and # continues processing. errorlevel = 1 # If 0, fatal errors only appear in debug # messages (if debug >= 0). If > 0, errors # are passed to the caller as exceptions. format = DEFAULT_FORMAT # The format to use when creating an archive. encoding = ENCODING # Encoding for 8-bit character strings. errors = None # Error handler for unicode conversion. tarinfo = TarInfo # The default TarInfo class to use. fileobject = ExFileObject # The default ExFileObject class to use. def __init__(self, name=None, mode="r", fileobj=None, format=None, tarinfo=None, dereference=None, ignore_zeros=None, encoding=None, errors=None, pax_headers=None, debug=None, errorlevel=None): """Open an (uncompressed) tar archive `name'. `mode' is either 'r' to read from an existing archive, 'a' to append data to an existing file or 'w' to create a new file overwriting an existing one. `mode' defaults to 'r'. If `fileobj' is given, it is used for reading or writing data. If it can be determined, `mode' is overridden by `fileobj's mode. `fileobj' is not closed, when TarFile is closed. """ modes = {"r": "rb", "a": "r+b", "w": "wb"} if mode not in modes: raise ValueError("mode must be 'r', 'a' or 'w'") self.mode = mode self._mode = modes[mode] if not fileobj: if self.mode == "a" and not os.path.exists(name): # Create nonexistent files in append mode. self.mode = "w" self._mode = "wb" fileobj = bltn_open(name, self._mode) self._extfileobj = False else: if name is None and hasattr(fileobj, "name"): name = fileobj.name if hasattr(fileobj, "mode"): self._mode = fileobj.mode self._extfileobj = True self.name = os.path.abspath(name) if name else None self.fileobj = fileobj # Init attributes. if format is not None: self.format = format if tarinfo is not None: self.tarinfo = tarinfo if dereference is not None: self.dereference = dereference if ignore_zeros is not None: self.ignore_zeros = ignore_zeros if encoding is not None: self.encoding = encoding if errors is not None: self.errors = errors elif mode == "r": self.errors = "utf-8" else: self.errors = "strict" if pax_headers is not None and self.format == PAX_FORMAT: self.pax_headers = pax_headers else: self.pax_headers = {} if debug is not None: self.debug = debug if errorlevel is not None: self.errorlevel = errorlevel # Init datastructures. self.closed = False self.members = [] # list of members as TarInfo objects self._loaded = False # flag if all members have been read self.offset = self.fileobj.tell() # current position in the archive file self.inodes = {} # dictionary caching the inodes of # archive members already added try: if self.mode == "r": self.firstmember = None self.firstmember = self.next() if self.mode == "a": # Move to the end of the archive, # before the first empty block. while True: self.fileobj.seek(self.offset) try: tarinfo = self.tarinfo.fromtarfile(self) self.members.append(tarinfo) except EOFHeaderError: self.fileobj.seek(self.offset) break except HeaderError, e: raise ReadError(str(e)) if self.mode in "aw": self._loaded = True if self.pax_headers: buf = self.tarinfo.create_pax_global_header(self.pax_headers.copy()) self.fileobj.write(buf) self.offset += len(buf) except: if not self._extfileobj: self.fileobj.close() self.closed = True raise def _getposix(self): return self.format == USTAR_FORMAT def _setposix(self, value): import warnings warnings.warn("use the format attribute instead", DeprecationWarning, 2) if value: self.format = USTAR_FORMAT else: self.format = GNU_FORMAT posix = property(_getposix, _setposix) #-------------------------------------------------------------------------- # Below are the classmethods which act as alternate constructors to the # TarFile class. The open() method is the only one that is needed for # public use; it is the "super"-constructor and is able to select an # adequate "sub"-constructor for a particular compression using the mapping # from OPEN_METH. # # This concept allows one to subclass TarFile without losing the comfort of # the super-constructor. A sub-constructor is registered and made available # by adding it to the mapping in OPEN_METH. @classmethod def open(cls, name=None, mode="r", fileobj=None, bufsize=RECORDSIZE, **kwargs): """Open a tar archive for reading, writing or appending. Return an appropriate TarFile class. mode: 'r' or 'r:*' open for reading with transparent compression 'r:' open for reading exclusively uncompressed 'r:gz' open for reading with gzip compression 'r:bz2' open for reading with bzip2 compression 'a' or 'a:' open for appending, creating the file if necessary 'w' or 'w:' open for writing without compression 'w:gz' open for writing with gzip compression 'w:bz2' open for writing with bzip2 compression 'r|*' open a stream of tar blocks with transparent compression 'r|' open an uncompressed stream of tar blocks for reading 'r|gz' open a gzip compressed stream of tar blocks 'r|bz2' open a bzip2 compressed stream of tar blocks 'w|' open an uncompressed stream for writing 'w|gz' open a gzip compressed stream for writing 'w|bz2' open a bzip2 compressed stream for writing """ if not name and not fileobj: raise ValueError("nothing to open") if mode in ("r", "r:*"): # Find out which *open() is appropriate for opening the file. for comptype in cls.OPEN_METH: func = getattr(cls, cls.OPEN_METH[comptype]) if fileobj is not None: saved_pos = fileobj.tell() try: return func(name, "r", fileobj, **kwargs) except (ReadError, CompressionError), e: if fileobj is not None: fileobj.seek(saved_pos) continue raise ReadError("file could not be opened successfully") elif ":" in mode: filemode, comptype = mode.split(":", 1) filemode = filemode or "r" comptype = comptype or "tar" # Select the *open() function according to # given compression. if comptype in cls.OPEN_METH: func = getattr(cls, cls.OPEN_METH[comptype]) else: raise CompressionError("unknown compression type %r" % comptype) return func(name, filemode, fileobj, **kwargs) elif "|" in mode: filemode, comptype = mode.split("|", 1) filemode = filemode or "r" comptype = comptype or "tar" if filemode not in ("r", "w"): raise ValueError("mode must be 'r' or 'w'") stream = _Stream(name, filemode, comptype, fileobj, bufsize) try: t = cls(name, filemode, stream, **kwargs) except: stream.close() raise t._extfileobj = False return t elif mode in ("a", "w"): return cls.taropen(name, mode, fileobj, **kwargs) raise ValueError("undiscernible mode") @classmethod def taropen(cls, name, mode="r", fileobj=None, **kwargs): """Open uncompressed tar archive name for reading or writing. """ if mode not in ("r", "a", "w"): raise ValueError("mode must be 'r', 'a' or 'w'") return cls(name, mode, fileobj, **kwargs) @classmethod def gzopen(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs): """Open gzip compressed tar archive name for reading or writing. Appending is not allowed. """ if mode not in ("r", "w"): raise ValueError("mode must be 'r' or 'w'") try: import gzip gzip.GzipFile except (ImportError, AttributeError): raise CompressionError("gzip module is not available") try: fileobj = gzip.GzipFile(name, mode, compresslevel, fileobj) except OSError: if fileobj is not None and mode == 'r': raise ReadError("not a gzip file") raise try: t = cls.taropen(name, mode, fileobj, **kwargs) except IOError: fileobj.close() if mode == 'r': raise ReadError("not a gzip file") raise except: fileobj.close() raise t._extfileobj = False return t @classmethod def bz2open(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs): """Open bzip2 compressed tar archive name for reading or writing. Appending is not allowed. """ if mode not in ("r", "w"): raise ValueError("mode must be 'r' or 'w'.") try: import bz2 except ImportError: raise CompressionError("bz2 module is not available") if fileobj is not None: fileobj = _BZ2Proxy(fileobj, mode) else: fileobj = bz2.BZ2File(name, mode, compresslevel=compresslevel) try: t = cls.taropen(name, mode, fileobj, **kwargs) except (IOError, EOFError): fileobj.close() if mode == 'r': raise ReadError("not a bzip2 file") raise except: fileobj.close() raise t._extfileobj = False return t # All *open() methods are registered here. OPEN_METH = { "tar": "taropen", # uncompressed tar "gz": "gzopen", # gzip compressed tar "bz2": "bz2open" # bzip2 compressed tar } #-------------------------------------------------------------------------- # The public methods which TarFile provides: def close(self): """Close the TarFile. In write-mode, two finishing zero blocks are appended to the archive. """ if self.closed: return if self.mode in "aw": self.fileobj.write(NUL * (BLOCKSIZE * 2)) self.offset += (BLOCKSIZE * 2) # fill up the end with zero-blocks # (like option -b20 for tar does) blocks, remainder = divmod(self.offset, RECORDSIZE) if remainder > 0: self.fileobj.write(NUL * (RECORDSIZE - remainder)) if not self._extfileobj: self.fileobj.close() self.closed = True def getmember(self, name): """Return a TarInfo object for member `name'. If `name' can not be found in the archive, KeyError is raised. If a member occurs more than once in the archive, its last occurrence is assumed to be the most up-to-date version. """ tarinfo = self._getmember(name) if tarinfo is None: raise KeyError("filename %r not found" % name) return tarinfo def getmembers(self): """Return the members of the archive as a list of TarInfo objects. The list has the same order as the members in the archive. """ self._check() if not self._loaded: # if we want to obtain a list of self._load() # all members, we first have to # scan the whole archive. return self.members def getnames(self): """Return the members of the archive as a list of their names. It has the same order as the list returned by getmembers(). """ return [tarinfo.name for tarinfo in self.getmembers()] def gettarinfo(self, name=None, arcname=None, fileobj=None): """Create a TarInfo object for either the file `name' or the file object `fileobj' (using os.fstat on its file descriptor). You can modify some of the TarInfo's attributes before you add it using addfile(). If given, `arcname' specifies an alternative name for the file in the archive. """ self._check("aw") # When fileobj is given, replace name by # fileobj's real name. if fileobj is not None: name = fileobj.name # Building the name of the member in the archive. # Backward slashes are converted to forward slashes, # Absolute paths are turned to relative paths. if arcname is None: arcname = name drv, arcname = os.path.splitdrive(arcname) arcname = arcname.replace(os.sep, "/") arcname = arcname.lstrip("/") # Now, fill the TarInfo object with # information specific for the file. tarinfo = self.tarinfo() tarinfo.tarfile = self # Use os.stat or os.lstat, depending on platform # and if symlinks shall be resolved. if fileobj is None: if hasattr(os, "lstat") and not self.dereference: statres = os.lstat(name) else: statres = os.stat(name) else: statres = os.fstat(fileobj.fileno()) linkname = "" stmd = statres.st_mode if stat.S_ISREG(stmd): inode = (statres.st_ino, statres.st_dev) if not self.dereference and statres.st_nlink > 1 and \ inode in self.inodes and arcname != self.inodes[inode]: # Is it a hardlink to an already # archived file? type = LNKTYPE linkname = self.inodes[inode] else: # The inode is added only if its valid. # For win32 it is always 0. type = REGTYPE if inode[0]: self.inodes[inode] = arcname elif stat.S_ISDIR(stmd): type = DIRTYPE elif stat.S_ISFIFO(stmd): type = FIFOTYPE elif stat.S_ISLNK(stmd): type = SYMTYPE linkname = os.readlink(name) elif stat.S_ISCHR(stmd): type = CHRTYPE elif stat.S_ISBLK(stmd): type = BLKTYPE else: return None # Fill the TarInfo object with all # information we can get. tarinfo.name = arcname tarinfo.mode = stmd tarinfo.uid = statres.st_uid tarinfo.gid = statres.st_gid if type == REGTYPE: tarinfo.size = statres.st_size else: tarinfo.size = 0L tarinfo.mtime = statres.st_mtime tarinfo.type = type tarinfo.linkname = linkname if pwd: try: tarinfo.uname = pwd.getpwuid(tarinfo.uid)[0] except KeyError: pass if grp: try: tarinfo.gname = grp.getgrgid(tarinfo.gid)[0] except KeyError: pass if type in (CHRTYPE, BLKTYPE): if hasattr(os, "major") and hasattr(os, "minor"): tarinfo.devmajor = os.major(statres.st_rdev) tarinfo.devminor = os.minor(statres.st_rdev) return tarinfo def list(self, verbose=True): """Print a table of contents to sys.stdout. If `verbose' is False, only the names of the members are printed. If it is True, an `ls -l'-like output is produced. """ self._check() for tarinfo in self: if verbose: print filemode(tarinfo.mode), print "%s/%s" % (tarinfo.uname or tarinfo.uid, tarinfo.gname or tarinfo.gid), if tarinfo.ischr() or tarinfo.isblk(): print "%10s" % ("%d,%d" \ % (tarinfo.devmajor, tarinfo.devminor)), else: print "%10d" % tarinfo.size, print "%d-%02d-%02d %02d:%02d:%02d" \ % time.localtime(tarinfo.mtime)[:6], print tarinfo.name + ("/" if tarinfo.isdir() else ""), if verbose: if tarinfo.issym(): print "->", tarinfo.linkname, if tarinfo.islnk(): print "link to", tarinfo.linkname, print def add(self, name, arcname=None, recursive=True, exclude=None, filter=None): """Add the file `name' to the archive. `name' may be any type of file (directory, fifo, symbolic link, etc.). If given, `arcname' specifies an alternative name for the file in the archive. Directories are added recursively by default. This can be avoided by setting `recursive' to False. `exclude' is a function that should return True for each filename to be excluded. `filter' is a function that expects a TarInfo object argument and returns the changed TarInfo object, if it returns None the TarInfo object will be excluded from the archive. """ self._check("aw") if arcname is None: arcname = name # Exclude pathnames. if exclude is not None: import warnings warnings.warn("use the filter argument instead", DeprecationWarning, 2) if exclude(name): self._dbg(2, "tarfile: Excluded %r" % name) return # Skip if somebody tries to archive the archive... if self.name is not None and os.path.abspath(name) == self.name: self._dbg(2, "tarfile: Skipped %r" % name) return self._dbg(1, name) # Create a TarInfo object from the file. tarinfo = self.gettarinfo(name, arcname) if tarinfo is None: self._dbg(1, "tarfile: Unsupported type %r" % name) return # Change or exclude the TarInfo object. if filter is not None: tarinfo = filter(tarinfo) if tarinfo is None: self._dbg(2, "tarfile: Excluded %r" % name) return # Append the tar header and data to the archive. if tarinfo.isreg(): with bltn_open(name, "rb") as f: self.addfile(tarinfo, f) elif tarinfo.isdir(): self.addfile(tarinfo) if recursive: for f in os.listdir(name): self.add(os.path.join(name, f), os.path.join(arcname, f), recursive, exclude, filter) else: self.addfile(tarinfo) def addfile(self, tarinfo, fileobj=None): """Add the TarInfo object `tarinfo' to the archive. If `fileobj' is given, tarinfo.size bytes are read from it and added to the archive. You can create TarInfo objects using gettarinfo(). On Windows platforms, `fileobj' should always be opened with mode 'rb' to avoid irritation about the file size. """ self._check("aw") tarinfo = copy.copy(tarinfo) buf = tarinfo.tobuf(self.format, self.encoding, self.errors) self.fileobj.write(buf) self.offset += len(buf) # If there's data to follow, append it. if fileobj is not None: copyfileobj(fileobj, self.fileobj, tarinfo.size) blocks, remainder = divmod(tarinfo.size, BLOCKSIZE) if remainder > 0: self.fileobj.write(NUL * (BLOCKSIZE - remainder)) blocks += 1 self.offset += blocks * BLOCKSIZE self.members.append(tarinfo) def extractall(self, path=".", members=None): """Extract all members from the archive to the current working directory and set owner, modification time and permissions on directories afterwards. `path' specifies a different directory to extract to. `members' is optional and must be a subset of the list returned by getmembers(). """ directories = [] if members is None: members = self for tarinfo in members: if tarinfo.isdir(): # Extract directories with a safe mode. directories.append(tarinfo) tarinfo = copy.copy(tarinfo) tarinfo.mode = 0700 self.extract(tarinfo, path) # Reverse sort directories. directories.sort(key=operator.attrgetter('name')) directories.reverse() # Set correct owner, mtime and filemode on directories. for tarinfo in directories: dirpath = os.path.join(path, tarinfo.name) try: self.chown(tarinfo, dirpath) self.utime(tarinfo, dirpath) self.chmod(tarinfo, dirpath) except ExtractError, e: if self.errorlevel > 1: raise else: self._dbg(1, "tarfile: %s" % e) def extract(self, member, path=""): """Extract a member from the archive to the current working directory, using its full name. Its file information is extracted as accurately as possible. `member' may be a filename or a TarInfo object. You can specify a different directory using `path'. """ self._check("r") if isinstance(member, basestring): tarinfo = self.getmember(member) else: tarinfo = member # Prepare the link target for makelink(). if tarinfo.islnk(): tarinfo._link_target = os.path.join(path, tarinfo.linkname) try: self._extract_member(tarinfo, os.path.join(path, tarinfo.name)) except EnvironmentError, e: if self.errorlevel > 0: raise else: if e.filename is None: self._dbg(1, "tarfile: %s" % e.strerror) else: self._dbg(1, "tarfile: %s %r" % (e.strerror, e.filename)) except ExtractError, e: if self.errorlevel > 1: raise else: self._dbg(1, "tarfile: %s" % e) def extractfile(self, member): """Extract a member from the archive as a file object. `member' may be a filename or a TarInfo object. If `member' is a regular file, a file-like object is returned. If `member' is a link, a file-like object is constructed from the link's target. If `member' is none of the above, None is returned. The file-like object is read-only and provides the following methods: read(), readline(), readlines(), seek() and tell() """ self._check("r") if isinstance(member, basestring): tarinfo = self.getmember(member) else: tarinfo = member if tarinfo.isreg(): return self.fileobject(self, tarinfo) elif tarinfo.type not in SUPPORTED_TYPES: # If a member's type is unknown, it is treated as a # regular file. return self.fileobject(self, tarinfo) elif tarinfo.islnk() or tarinfo.issym(): if isinstance(self.fileobj, _Stream): # A small but ugly workaround for the case that someone tries # to extract a (sym)link as a file-object from a non-seekable # stream of tar blocks. raise StreamError("cannot extract (sym)link as file object") else: # A (sym)link's file object is its target's file object. return self.extractfile(self._find_link_target(tarinfo)) else: # If there's no data associated with the member (directory, chrdev, # blkdev, etc.), return None instead of a file object. return None def _extract_member(self, tarinfo, targetpath): """Extract the TarInfo object tarinfo to a physical file called targetpath. """ # Fetch the TarInfo object for the given name # and build the destination pathname, replacing # forward slashes to platform specific separators. targetpath = targetpath.rstrip("/") targetpath = targetpath.replace("/", os.sep) # Create all upper directories. upperdirs = os.path.dirname(targetpath) if upperdirs and not os.path.exists(upperdirs): # Create directories that are not part of the archive with # default permissions. os.makedirs(upperdirs) if tarinfo.islnk() or tarinfo.issym(): self._dbg(1, "%s -> %s" % (tarinfo.name, tarinfo.linkname)) else: self._dbg(1, tarinfo.name) if tarinfo.isreg(): self.makefile(tarinfo, targetpath) elif tarinfo.isdir(): self.makedir(tarinfo, targetpath) elif tarinfo.isfifo(): self.makefifo(tarinfo, targetpath) elif tarinfo.ischr() or tarinfo.isblk(): self.makedev(tarinfo, targetpath) elif tarinfo.islnk() or tarinfo.issym(): self.makelink(tarinfo, targetpath) elif tarinfo.type not in SUPPORTED_TYPES: self.makeunknown(tarinfo, targetpath) else: self.makefile(tarinfo, targetpath) self.chown(tarinfo, targetpath) if not tarinfo.issym(): self.chmod(tarinfo, targetpath) self.utime(tarinfo, targetpath) #-------------------------------------------------------------------------- # Below are the different file methods. They are called via # _extract_member() when extract() is called. They can be replaced in a # subclass to implement other functionality. def makedir(self, tarinfo, targetpath): """Make a directory called targetpath. """ try: # Use a safe mode for the directory, the real mode is set # later in _extract_member(). os.mkdir(targetpath, 0700) except EnvironmentError, e: if e.errno != errno.EEXIST: raise def makefile(self, tarinfo, targetpath): """Make a file called targetpath. """ source = self.extractfile(tarinfo) try: with bltn_open(targetpath, "wb") as target: copyfileobj(source, target) finally: source.close() def makeunknown(self, tarinfo, targetpath): """Make a file from a TarInfo object with an unknown type at targetpath. """ self.makefile(tarinfo, targetpath) self._dbg(1, "tarfile: Unknown file type %r, " \ "extracted as regular file." % tarinfo.type) def makefifo(self, tarinfo, targetpath): """Make a fifo called targetpath. """ if hasattr(os, "mkfifo"): os.mkfifo(targetpath) else: raise ExtractError("fifo not supported by system") def makedev(self, tarinfo, targetpath): """Make a character or block device called targetpath. """ if not hasattr(os, "mknod") or not hasattr(os, "makedev"): raise ExtractError("special devices not supported by system") mode = tarinfo.mode if tarinfo.isblk(): mode |= stat.S_IFBLK else: mode |= stat.S_IFCHR os.mknod(targetpath, mode, os.makedev(tarinfo.devmajor, tarinfo.devminor)) def makelink(self, tarinfo, targetpath): """Make a (symbolic) link called targetpath. If it cannot be created (platform limitation), we try to make a copy of the referenced file instead of a link. """ if hasattr(os, "symlink") and hasattr(os, "link"): # For systems that support symbolic and hard links. if tarinfo.issym(): if os.path.lexists(targetpath): os.unlink(targetpath) os.symlink(tarinfo.linkname, targetpath) else: # See extract(). if os.path.exists(tarinfo._link_target): if os.path.lexists(targetpath): os.unlink(targetpath) os.link(tarinfo._link_target, targetpath) else: self._extract_member(self._find_link_target(tarinfo), targetpath) else: try: self._extract_member(self._find_link_target(tarinfo), targetpath) except KeyError: raise ExtractError("unable to resolve link inside archive") def chown(self, tarinfo, targetpath): """Set owner of targetpath according to tarinfo. """ if pwd and hasattr(os, "geteuid") and os.geteuid() == 0: # We have to be root to do so. try: g = grp.getgrnam(tarinfo.gname)[2] except KeyError: g = tarinfo.gid try: u = pwd.getpwnam(tarinfo.uname)[2] except KeyError: u = tarinfo.uid try: if tarinfo.issym() and hasattr(os, "lchown"): os.lchown(targetpath, u, g) else: if sys.platform != "os2emx": os.chown(targetpath, u, g) except EnvironmentError, e: raise ExtractError("could not change owner") def chmod(self, tarinfo, targetpath): """Set file permissions of targetpath according to tarinfo. """ if hasattr(os, 'chmod'): try: os.chmod(targetpath, tarinfo.mode) except EnvironmentError, e: raise ExtractError("could not change mode") def utime(self, tarinfo, targetpath): """Set modification time of targetpath according to tarinfo. """ if not hasattr(os, 'utime'): return try: os.utime(targetpath, (tarinfo.mtime, tarinfo.mtime)) except EnvironmentError, e: raise ExtractError("could not change modification time") #-------------------------------------------------------------------------- def next(self): """Return the next member of the archive as a TarInfo object, when TarFile is opened for reading. Return None if there is no more available. """ self._check("ra") if self.firstmember is not None: m = self.firstmember self.firstmember = None return m # Read the next block. self.fileobj.seek(self.offset) tarinfo = None while True: try: tarinfo = self.tarinfo.fromtarfile(self) except EOFHeaderError, e: if self.ignore_zeros: self._dbg(2, "0x%X: %s" % (self.offset, e)) self.offset += BLOCKSIZE continue except InvalidHeaderError, e: if self.ignore_zeros: self._dbg(2, "0x%X: %s" % (self.offset, e)) self.offset += BLOCKSIZE continue elif self.offset == 0: raise ReadError(str(e)) except EmptyHeaderError: if self.offset == 0: raise ReadError("empty file") except TruncatedHeaderError, e: if self.offset == 0: raise ReadError(str(e)) except SubsequentHeaderError, e: raise ReadError(str(e)) break if tarinfo is not None: self.members.append(tarinfo) else: self._loaded = True return tarinfo #-------------------------------------------------------------------------- # Little helper methods: def _getmember(self, name, tarinfo=None, normalize=False): """Find an archive member by name from bottom to top. If tarinfo is given, it is used as the starting point. """ # Ensure that all members have been loaded. members = self.getmembers() # Limit the member search list up to tarinfo. if tarinfo is not None: members = members[:members.index(tarinfo)] if normalize: name = os.path.normpath(name) for member in reversed(members): if normalize: member_name = os.path.normpath(member.name) else: member_name = member.name if name == member_name: return member def _load(self): """Read through the entire archive file and look for readable members. """ while True: tarinfo = self.next() if tarinfo is None: break self._loaded = True def _check(self, mode=None): """Check if TarFile is still open, and if the operation's mode corresponds to TarFile's mode. """ if self.closed: raise IOError("%s is closed" % self.__class__.__name__) if mode is not None and self.mode not in mode: raise IOError("bad operation for mode %r" % self.mode) def _find_link_target(self, tarinfo): """Find the target member of a symlink or hardlink member in the archive. """ if tarinfo.issym(): # Always search the entire archive. linkname = "/".join(filter(None, (os.path.dirname(tarinfo.name), tarinfo.linkname))) limit = None else: # Search the archive before the link, because a hard link is # just a reference to an already archived file. linkname = tarinfo.linkname limit = tarinfo member = self._getmember(linkname, tarinfo=limit, normalize=True) if member is None: raise KeyError("linkname %r not found" % linkname) return member def __iter__(self): """Provide an iterator object. """ if self._loaded: return iter(self.members) else: return TarIter(self) def _dbg(self, level, msg): """Write debugging output to sys.stderr. """ if level <= self.debug: print >> sys.stderr, msg def __enter__(self): self._check() return self def __exit__(self, type, value, traceback): if type is None: self.close() else: # An exception occurred. We must not call close() because # it would try to write end-of-archive blocks and padding. if not self._extfileobj: self.fileobj.close() self.closed = True # class TarFile TarFile
用於序列化的兩個模塊
Json模塊提供了四個功能:dumps、dump、loads、load
pickle模塊提供了四個功能:dumps、dump、loads、load
shelve模塊是一個簡單的k,v將內存數據經過文件持久化的模塊,能夠持久化任何pickle可支持的python數據格式
import shelve d = shelve.open('shelve_test') #打開一個文件 class Test(object): def __init__(self,n): self.n = n t = Test(123) t2 = Test(123334) name = ["alex","rain","test"] d["test"] = name #持久化列表 d["t1"] = t #持久化類 d["t2"] = t2 d.close()
反序列化
d1 = shelve.open("shelve.txt") print(d1["test"]) dd1 = d1["t1"] print(dd1) print(dd1.n) dd2 = d1["t2"] print(dd2) print(dd2.n)
結果:
['alex', 'rain', 'golf'] <__main__.Test object at 0x000000000295E5C0> 123 <__main__.Test object at 0x000000000295E588> 456789
xml是實現不一樣語言或程序之間進行數據交換的協議,跟json差很少,但json使用起來更簡單,不過,古時候,在json還沒誕生的黑暗年代,你們只能選擇用xml呀,至今不少傳統公司如金融行業的不少系統的接口還主要是xml。
xml的格式以下,就是經過<>節點來區別數據結構的:
<?xml version="1.0"?> <data> <country name="Liechtenstein"> <rank updated="yes">2</rank> <year>2008</year> <gdppc>141100</gdppc> <neighbor name="Austria" direction="E"/> <neighbor name="Switzerland" direction="W"/> </country> <country name="Singapore"> <rank updated="yes">5</rank> <year>2011</year> <gdppc>59900</gdppc> <neighbor name="Malaysia" direction="N"/> </country> <country name="Panama"> <rank updated="yes">69</rank> <year>2011</year> <gdppc>13600</gdppc> <neighbor name="Costa Rica" direction="W"/> <neighbor name="Colombia" direction="E"/> </country> </data>
xml協議在各個語言裏的都 是支持的,在python中能夠用如下模塊操做xml
import xml.etree.ElementTree as ET tree = ET.parse("xmltest.xml") root = tree.getroot() print(root.tag) #遍歷xml文檔 for child in root: print(child.tag, child.attrib) for i in child: print(i.tag,i.text) #只遍歷year 節點 for node in root.iter('year'): print(node.tag,node.text)
修改和刪除xml文檔內容
import xml.etree.ElementTree as ET tree = ET.parse("xmltest.xml") root = tree.getroot() #修改 for node in root.iter('year'): new_year = int(node.text) + 1 node.text = str(new_year) node.set("updated","yes") tree.write("xmltest.xml") #刪除node for country in root.findall('country'): rank = int(country.find('rank').text) if rank > 50: root.remove(country) tree.write('output.xml')
本身建立xml文檔
import xml.etree.ElementTree as ET new_xml = ET.Element("namelist") name = ET.SubElement(new_xml,"name",attrib={"enrolled":"yes"}) age = ET.SubElement(name,"age",attrib={"checked":"no"}) sex = ET.SubElement(name,"sex") sex.text = '33' name2 = ET.SubElement(new_xml,"name",attrib={"enrolled":"no"}) age = ET.SubElement(name2,"age") age.text = '19' et = ET.ElementTree(new_xml) #生成文檔對象 et.write("test.xml", encoding="utf-8",xml_declaration=True) ET.dump(new_xml) #打印生成的格式
Python也能夠很容易的處理ymal文檔格式,只不過須要安裝一個模塊,參考文檔:http://pyyaml.org/wiki/PyYAMLDocumentation
用於生成和修改常見配置文檔,當前模塊的名稱在 python 3.x 版本中變動爲 configparser。
來看一個好多軟件的常見文檔格式以下
[DEFAULT] ServerAliveInterval = 45 Compression = yes CompressionLevel = 9 ForwardX11 = yes [bitbucket.org] User = hg [topsecret.server.com] Port = 50022 ForwardX11 = no
若是想用python生成一個這樣的文檔怎麼作呢?
import configparser config = configparser.ConfigParser() config["DEFAULT"] = {'ServerAliveInterval': '45', 'Compression': 'yes', 'CompressionLevel': '9'} config['bitbucket.org'] = {} config['bitbucket.org']['User'] = 'hg' config['topsecret.server.com'] = {} topsecret = config['topsecret.server.com'] topsecret['Host Port'] = '50022' # mutates the parser topsecret['ForwardX11'] = 'no' # same here config['DEFAULT']['ForwardX11'] = 'yes' with open('example.ini', 'w') as configfile: config.write(configfile)
寫完了還能夠再讀出來哈。
>>> import configparser >>> config = configparser.ConfigParser() >>> config.sections() [] >>> config.read('example.ini') ['example.ini'] >>> config.sections() ['bitbucket.org', 'topsecret.server.com'] >>> 'bitbucket.org' in config True >>> 'bytebong.com' in config False >>> config['bitbucket.org']['User'] 'hg' >>> config['DEFAULT']['Compression'] 'yes' >>> topsecret = config['topsecret.server.com'] >>> topsecret['ForwardX11'] 'no' >>> topsecret['Port'] '50022' >>> for key in config['bitbucket.org']: print(key) ... user compressionlevel serveraliveinterval compression forwardx11 >>> config['bitbucket.org']['ForwardX11'] 'yes'
configparser增刪改查語法
[section1] k1 = v1 k2:v2 [section2] k1 = v1 import ConfigParser config = ConfigParser.ConfigParser() config.read('i.cfg') # ########## 讀 ########## #secs = config.sections() #print secs #options = config.options('group2') #print options #item_list = config.items('group2') #print item_list #val = config.get('group1','key') #val = config.getint('group1','key') # ########## 改寫 ########## #sec = config.remove_section('group1') #config.write(open('i.cfg', "w")) #sec = config.has_section('wupeiqi') #sec = config.add_section('wupeiqi') #config.write(open('i.cfg', "w")) #config.set('group2','k1',11111) #config.write(open('i.cfg', "w")) #config.remove_option('group2','age') #config.write(open('i.cfg', "w"))
hashlib模塊
用於加密相關的操做,3.x裏代替了md5模塊和sha模塊,主要提供 SHA1, SHA224, SHA256, SHA384, SHA512 ,MD5 算法
import hashlib m = hashlib.md5() m.update(b"Hello") m.update(b"It's me") print(m.digest()) m.update(b"It's been a long time since last time we ...") print(m.digest()) #2進制格式hash print(len(m.hexdigest())) #16進制格式hash ''' def digest(self, *args, **kwargs): # real signature unknown """ Return the digest value as a string of binary data. """ pass def hexdigest(self, *args, **kwargs): # real signature unknown """ Return the digest value as a string of hexadecimal digits. """ pass ''' import hashlib # ######## md5 ######## hash = hashlib.md5() hash.update('admin') print(hash.hexdigest()) # ######## sha1 ######## hash = hashlib.sha1() hash.update('admin') print(hash.hexdigest()) # ######## sha256 ######## hash = hashlib.sha256() hash.update('admin') print(hash.hexdigest()) # ######## sha384 ######## hash = hashlib.sha384() hash.update('admin') print(hash.hexdigest()) # ######## sha512 ######## hash = hashlib.sha512() hash.update('admin') print(hash.hexdigest())
還不夠吊?python 還有一個 hmac 模塊,它內部對咱們建立 key 和 內容 再進行處理而後再加密
散列消息鑑別碼,簡稱HMAC,是一種基於消息鑑別碼MAC(Message Authentication Code)的鑑別機制。使用HMAC時,消息通信的雙方,經過驗證消息中加入的鑑別密鑰K來鑑別消息的真僞;
通常用於網絡通訊中消息加密,前提是雙方先要約定好key,就像接頭暗號同樣,而後消息發送把用key把消息加密,接收方用key + 消息明文再加密,拿加密後的值 跟 發送者的相對比是否相等,這樣就能驗證消息的真實性,及發送者的合法性了。
import hmac h = hmac.new(b'天王蓋地虎', b'寶塔鎮河妖') print h.hexdigest()
更多關於md5,sha1,sha256等介紹的文章看這裏https://www.tbs-certificates.co.uk/FAQ/en/sha256.html
The subprocess
module allows you to spawn new processes, connect to their input/output/error pipes, and obtain their return codes. This module intends to replace several older modules and functions:
os.system os.spawn*
The recommended approach to invoking subprocesses is to use the run()
function for all use cases it can handle. For more advanced use cases, the underlying Popen
interface can be used directly.
The run()
function was added in Python 3.5; if you need to retain compatibility with older versions, see the Older high-level API section.
(args, *, stdin=None, input=None, stdout=None, stderr=None, shell=False, timeout=None, check=False)subprocess.run
Run the command described by args. Wait for command to complete, then return a CompletedProcess
instance.
The arguments shown above are merely the most common ones, described below in Frequently Used Arguments (hence the use of keyword-only notation in the abbreviated signature). The full function signature is largely the same as that of the Popen
constructor - apart from timeout, input and check, all the arguments to this function are passed through to that interface.
This does not capture stdout or stderr by default. To do so, pass PIPE
for the stdout and/or stderr arguments.
The timeout argument is passed to Popen.communicate()
. If the timeout expires, the child process will be killed and waited for. The TimeoutExpired
exception will be re-raised after the child process has terminated.
The input argument is passed to Popen.communicate()
and thus to the subprocess’s stdin. If used it must be a byte sequence, or a string if universal_newlines=True
. When used, the internal Popen
object is automatically created withstdin=PIPE
, and the stdin argument may not be used as well.
If check is True, and the process exits with a non-zero exit code, a CalledProcessError
exception will be raised. Attributes of that exception hold the arguments, the exit code, and stdout and stderr if they were captured.
#執行命令,返回命令執行狀態 , 0 or 非0
>>> retcode = subprocess.call(["ls", "-l"])
#執行命令,若是命令結果爲0,就正常返回,不然拋異常
>>> subprocess.check_call(["ls", "-l"])
0
#接收字符串格式命令,返回元組形式,第1個元素是執行狀態,第2個是命令結果
>>> subprocess.getstatusoutput('ls /bin/ls')
(0, '/bin/ls')
#接收字符串格式命令,並返回結果
>>> subprocess.getoutput('ls /bin/ls')
'/bin/ls'
#執行命令,並返回結果,注意是返回結果,不是打印,下例結果返回給res
>>> res=subprocess.check_output(['ls','-l'])
>>> res
b'total 0\ndrwxr-xr-x 12 alex staff 408 Nov 2 11:05 OldBoyCRM\n'
#上面那些方法,底層都是封裝的subprocess.Popen
poll()
Check if child process has terminated. Returns returncode
wait()
Wait for child process to terminate. Returns returncode attribute.
terminate() 殺掉所啓動進程
communicate() 等待任務結束
stdin 標準輸入
stdout 標準輸出
stderr 標準錯誤
pid
The process ID of the child process.
#例子
>>> p = subprocess.Popen("df -h|grep disk",stdin=subprocess.PIPE,stdout=subprocess.PIPE,shell=True)
>>> p.stdout.read()
b'/dev/disk1 465Gi 64Gi 400Gi 14% 16901472 104938142 14% /\n'
>>> subprocess.run(["ls", "-l"]) # doesn't capture output CompletedProcess(args=['ls', '-l'], returncode=0) >>> subprocess.run("exit 1", shell=True, check=True) Traceback (most recent call last): ... subprocess.CalledProcessError: Command 'exit 1' returned non-zero exit status 1 >>> subprocess.run(["ls", "-l", "/dev/null"], stdout=subprocess.PIPE) CompletedProcess(args=['ls', '-l', '/dev/null'], returncode=0, stdout=b'crw-rw-rw- 1 root root 1, 3 Jan 23 16:23 /dev/null\n')
調用subprocess.run(...)是推薦的經常使用方法,在大多數狀況下能知足需求,但若是你可能須要進行一些複雜的與系統的交互的話,你還能夠用subprocess.Popen(),語法以下:
p = subprocess.Popen("find / -size +1000000 -exec ls -shl {} \;",shell=True,stdout=subprocess.PIPE) print(p.stdout.read())
可用參數:
終端輸入的命令分爲兩種:
須要交互的命令示例
import subprocess obj = subprocess.Popen(["python"], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE) obj.stdin.write('print 1 \n ') obj.stdin.write('print 2 \n ') obj.stdin.write('print 3 \n ') obj.stdin.write('print 4 \n ') out_error_list = obj.communicate(timeout=10) print out_error_list
import subprocess def mypass(): mypass = '123' #or get the password from anywhere return mypass echo = subprocess.Popen(['echo',mypass()], stdout=subprocess.PIPE, ) sudo = subprocess.Popen(['sudo','-S','iptables','-L'], stdin=echo.stdout, stdout=subprocess.PIPE, ) end_of_pipe = sudo.stdout print "Password ok \n Iptables Chains %s" % end_of_pipe.read()
不少程序都有記錄日誌的需求,而且日誌中包含的信息即有正常的程序訪問日誌,還可能有錯誤、警告等信息輸出,python的logging模塊提供了標準的日誌接口,你能夠經過它存儲各類格式的日誌,logging的日誌能夠分爲 debug(), info(), warning(), error() and critical() 5個級別,下面咱們看一下怎麼用。
import logging logging.warning("user [alex] attempted wrong password more than 3 times") logging.critical("server is down") #輸出 WARNING:root:user [alex] attempted wrong password more than 3 times CRITICAL:root:server is down
看一下這幾個日誌級別分別表明什麼意思
Level | When it’s used |
---|---|
DEBUG |
Detailed information, typically of interest only when diagnosing problems. |
INFO |
Confirmation that things are working as expected. |
WARNING |
An indication that something unexpected happened, or indicative of some problem in the near future (e.g. ‘disk space low’). The software is still working as expected. |
ERROR |
Due to a more serious problem, the software has not been able to perform some function. |
CRITICAL |
A serious error, indicating that the program itself may be unable to continue running. |
若是想把日誌寫到文件裏,也很簡單
import logging logging.basicConfig(filename='example.log',level=logging.INFO) logging.debug('This message should go to the log file') logging.info('So should this') logging.warning('And this, too')
其中下面這句中的level=loggin.INFO意思是,把日誌紀錄級別設置爲INFO,也就是說,只有比日誌是INFO或比INFO級別更高的日誌纔會被紀錄到文件裏,在這個例子, 第一條日誌是不會被紀錄的,若是但願紀錄debug的日誌,那把日誌級別改爲DEBUG就好了。
logging.basicConfig(filename='example.log',level=logging.INFO)
感受上面的日誌格式忘記加上時間啦,日誌不知道時間怎麼行呢,下面就來加上!
import logging logging.basicConfig(format='%(asctime)s %(message)s', datefmt='%m/%d/%Y %I:%M:%S %p') logging.warning('is when this event was logged.') #輸出 12/12/2010 11:46:36 AM is when this event was logged.
日誌格式
%(name)s |
Logger的名字 |
%(levelno)s |
數字形式的日誌級別 |
%(levelname)s |
文本形式的日誌級別 |
%(pathname)s |
調用日誌輸出函數的模塊的完整路徑名,可能沒有 |
%(filename)s |
調用日誌輸出函數的模塊的文件名 |
%(module)s |
調用日誌輸出函數的模塊名 |
%(funcName)s |
調用日誌輸出函數的函數名 |
%(lineno)d |
調用日誌輸出函數的語句所在的代碼行 |
%(created)f |
當前時間,用UNIX標準的表示時間的浮 點數表示 |
%(relativeCreated)d |
輸出日誌信息時的,自Logger建立以 來的毫秒數 |
%(asctime)s |
字符串形式的當前時間。默認格式是 「2003-07-08 16:49:45,896」。逗號後面的是毫秒 |
%(thread)d |
線程ID。可能沒有 |
%(threadName)s |
線程名。可能沒有 |
%(process)d |
進程ID。可能沒有 |
%(message)s |
用戶輸出的消息 |
若是想同時把log打印在屏幕和文件日誌裏,就須要瞭解一點複雜的知識 了
Python 使用logging模塊記錄日誌涉及四個主要類,使用官方文檔中的歸納最爲合適:
logger提供了應用程序能夠直接使用的接口;
handler將(logger建立的)日誌記錄發送到合適的目的輸出;
filter提供了細度設備來決定輸出哪條日誌記錄;
formatter決定日誌記錄的最終輸出格式。
logger
每一個程序在輸出信息以前都要得到一個Logger。Logger一般對應了程序的模塊名,好比聊天工具的圖形界面模塊能夠這樣得到它的Logger:
LOG=logging.getLogger(」chat.gui」)
而核心模塊能夠這樣:
LOG=logging.getLogger(」chat.kernel」)
Logger.setLevel(lel):指定最低的日誌級別,低於lel的級別將被忽略。debug是最低的內置級別,critical爲最高
Logger.addFilter(filt)、Logger.removeFilter(filt):添加或刪除指定的filter
Logger.addHandler(hdlr)、Logger.removeHandler(hdlr):增長或刪除指定的handler
Logger.debug()、Logger.info()、Logger.warning()、Logger.error()、Logger.critical():能夠設置的日誌級別
handler
handler對象負責發送相關的信息到指定目的地。Python的日誌系統有多種Handler可使用。有些Handler能夠把信息輸出到控制檯,有些Logger能夠把信息輸出到文件,還有些 Handler能夠把信息發送到網絡上。若是以爲不夠用,還能夠編寫本身的Handler。能夠經過addHandler()方法添加多個多handler
Handler.setLevel(lel):指定被處理的信息級別,低於lel級別的信息將被忽略
Handler.setFormatter():給這個handler選擇一個格式
Handler.addFilter(filt)、Handler.removeFilter(filt):新增或刪除一個filter對象
每一個Logger能夠附加多個Handler。接下來咱們就來介紹一些經常使用的Handler:
1) logging.StreamHandler
使用這個Handler能夠向相似與sys.stdout或者sys.stderr的任何文件對象(file object)輸出信息。它的構造函數是:
StreamHandler([strm])
其中strm參數是一個文件對象。默認是sys.stderr
2) logging.FileHandler
和StreamHandler相似,用於向一個文件輸出日誌信息。不過FileHandler會幫你打開這個文件。它的構造函數是:
FileHandler(filename[,mode])
filename是文件名,必須指定一個文件名。
mode是文件的打開方式。參見Python內置函數open()的用法。默認是’a',即添加到文件末尾。
3) logging.handlers.RotatingFileHandler
這個Handler相似於上面的FileHandler,可是它能夠管理文件大小。當文件達到必定大小以後,它會自動將當前日誌文件更名,而後建立 一個新的同名日誌文件繼續輸出。好比日誌文件是chat.log。當chat.log達到指定的大小以後,RotatingFileHandler自動把 文件更名爲chat.log.1。不過,若是chat.log.1已經存在,會先把chat.log.1重命名爲chat.log.2。。。最後從新建立 chat.log,繼續輸出日誌信息。它的構造函數是:
RotatingFileHandler( filename[, mode[, maxBytes[, backupCount]]])
其中filename和mode兩個參數和FileHandler同樣。
maxBytes用於指定日誌文件的最大文件大小。若是maxBytes爲0,意味着日誌文件能夠無限大,這時上面描述的重命名過程就不會發生。
backupCount用於指定保留的備份文件的個數。好比,若是指定爲2,當上面描述的重命名過程發生時,原有的chat.log.2並不會被改名,而是被刪除。
4) logging.handlers.TimedRotatingFileHandler
這個Handler和RotatingFileHandler相似,不過,它沒有經過判斷文件大小來決定什麼時候從新建立日誌文件,而是間隔必定時間就 自動建立新的日誌文件。重命名的過程與RotatingFileHandler相似,不過新的文件不是附加數字,而是當前時間。它的構造函數是:
TimedRotatingFileHandler( filename [,when [,interval [,backupCount]]])
其中filename參數和backupCount參數和RotatingFileHandler具備相同的意義。
interval是時間間隔。
when參數是一個字符串。表示時間間隔的單位,不區分大小寫。它有如下取值:
S 秒
M 分
H 小時
D 天
W 每星期(interval==0時表明星期一)
midnight 天天凌晨
import logging #create logger logger = logging.getLogger('TEST-LOG') logger.setLevel(logging.DEBUG) # create console handler and set level to debug ch = logging.StreamHandler() ch.setLevel(logging.DEBUG) # create file handler and set level to warning fh = logging.FileHandler("access.log") fh.setLevel(logging.WARNING) # create formatter formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s') # add formatter to ch and fh ch.setFormatter(formatter) fh.setFormatter(formatter) # add ch and fh to logger logger.addHandler(ch) logger.addHandler(fh) # 'application' code logger.debug('debug message') logger.info('info message') logger.warn('warn message') logger.error('error message') logger.critical('critical message')
文件自動截斷例子
import logging from logging import handlers logger = logging.getLogger(__name__) log_file = "timelog.log" #fh = handlers.RotatingFileHandler(filename=log_file,maxBytes=10,backupCount=3) fh = handlers.TimedRotatingFileHandler(filename=log_file,when="S",interval=5,backupCount=3) formatter = logging.Formatter('%(asctime)s %(module)s:%(lineno)d %(message)s') fh.setFormatter(formatter) logger.addHandler(fh) logger.warning("test1") logger.warning("test12") logger.warning("test13") logger.warning("test14")
用於便捷記錄日誌且線程安全的模塊
import logging logging.basicConfig(filename='log.log', format='%(asctime)s - %(name)s - %(levelname)s -%(module)s: %(message)s', datefmt='%Y-%m-%d %H:%M:%S %p', level=10) logging.debug('debug') logging.info('info') logging.warning('warning') logging.error('error') logging.critical('critical') logging.log(10,'log')
對於等級:
CRITICAL = 50 FATAL = CRITICAL ERROR = 40 WARNING = 30 WARN = WARNING INFO = 20 DEBUG = 10 NOTSET = 0
只有大於當前日誌等級的操做纔會被記錄。
對於格式,有以下屬性但是配置:
經常使用正則表達式符號
'.' 默認匹配除\n以外的任意一個字符,若指定flag DOTALL,則匹配任意字符,包括換行 '^' 匹配字符開頭,若指定flags MULTILINE,這種也能夠匹配上(r"^a","\nabc\neee",flags=re.MULTILINE) '$' 匹配字符結尾,或e.search("foo$","bfoo\nsdfsf",flags=re.MULTILINE).group()也能夠 '*' 匹配*號前的字符0次或屢次,re.findall("ab*","cabb3abcbbac") 結果爲['abb', 'ab', 'a'] '+' 匹配前一個字符1次或屢次,re.findall("ab+","ab+cd+abb+bba") 結果['ab', 'abb'] '?' 匹配前一個字符1次或0次 '{m}' 匹配前一個字符m次 '{n,m}' 匹配前一個字符n到m次,re.findall("ab{1,3}","abb abc abbcbbb") 結果'abb', 'ab', 'abb'] '|' 匹配|左或|右的字符,re.search("abc|ABC","ABCBabcCD").group() 結果'ABC' '(...)' 分組匹配,re.search("(abc){2}a(123|456)c", "abcabca456c").group() 結果 abcabca456c '\A' 只從字符開頭匹配,re.search("\Aabc","alexabc") 是匹配不到的 '\Z' 匹配字符結尾,同$ '\d' 匹配數字0-9 '\D' 匹配非數字 '\w' 匹配[A-Za-z0-9] '\W' 匹配非[A-Za-z0-9] 's' 匹配空白字符、\t、\n、\r , re.search("\s+","ab\tc1\n3").group() 結果 '\t' '(?P<name>...)' 分組匹配 re.search("(?P<province>[0-9]{4})(?P<city>[0-9]{2})(?P<birthday>[0-9]{4})","371481199306143242").groupdict("city") 結果{'province': '3714', 'city': '81', 'birthday': '1993'}
最經常使用的匹配語法
re.match 從頭開始匹配 re.search 匹配包含 re.findall 把全部匹配到的字符放到以列表中的元素返回 re.splitall 以匹配到的字符當作列表分隔符 re.sub 匹配字符並替換
反斜槓的困擾
與大多數編程語言相同,正則表達式裏使用"\"做爲轉義字符,這就可能形成反斜槓困擾。假如你須要匹配文本中的字符"\",那麼使用編程語言表示的正則表達式裏將須要4個反斜槓"\\\\":前兩個和後兩個分別用於在編程語言裏轉義成反斜槓,轉換成兩個反斜槓後再在正則表達式裏轉義成一個反斜槓。Python裏的原生字符串很好地解決了這個問題,這個例子中的正則表達式可使用r"\\"表示。一樣,匹配一個數字的"\\d"能夠寫成r"\d"。有了原生字符串,你不再用擔憂是否是漏寫了反斜槓,寫出來的表達式也更直觀。
僅需輕輕知道的幾個匹配模式
re.I(re.IGNORECASE): 忽略大小寫(括號內是完整寫法,下同) M(MULTILINE): 多行模式,改變'^'和'$'的行爲(參見上圖) S(DOTALL): 點任意匹配模式,改變'.'的行爲
開發一個簡單的python計算器