Python 技術點

一、文件操做

1-1 遍歷文件夾和文件

import os
rootDir = "/path/to/root"

for parent, dirnames, filenames in os.walk(rootDir):
    for dirname in dirnames:
        print("parent is:" + parent)
        print("dirname is:" + dirname)
    
    for filename in filenames:
        print("parent is:" + parent)
        print("filename is:" + filename)
        print("the full name of the file is:" + os.path.join(parent, filename))

1-2 獲取文件名和擴展名

import os
path = "/root/to/filename.txt"

name, ext = os.path.splitext(path)
print(name, ext)
print(os.path.dirname(path))
print(os.path.basename(path))

1-3 逐行讀取文本文件內容

f = open("/path/to/file.txt")

# The first method
line = f.readline()
while line:
    print(line)
    line = f.readline()
f.close()

# The second method
for line in open("/path/to/file.txt"):
    print(line)

# The third method
lines = f.readlines()
for line in lines:
    print(line)

1-4 寫文件

output = open("/path/to/file", "w")
# output = open("/path/to/file", "w+")

output.write(all_the_text)
# output.writelines(list_of_text_strings)

1-5 判斷文件是否存在

import os

os.path.exists("/path/to/file")
os.path.exists("/path/to/dir")

# Only check file
os.path.isfile("/path/to/file")

1-6 建立文件夾

import os

# Make multilayer directorys
os.makedirs("/path/to/dir")

# Make single directory
os.makedir("/path/to/dir")

二、其餘

2-1 數字前補 0

n = 123
m = -123

print(str(n).zfill(5))    # '00123'
print(str(m).zfill(5))    # '-0123'

print('%05d' % n)    # '00123'
print('%05d' % m)    # '-0123'

（未完待續）