python3_requests模塊詳解

時間 2019-11-11

標籤 python3 python requests 模塊詳解欄目 Python 简体版

原文原文鏈接

一、模塊說明

requests是使用Apache2 licensed 許可證的HTTP庫。php

用python編寫。html

比urllib2模塊更簡潔。python

Request支持HTTP鏈接保持和鏈接池，支持使用cookie保持會話，支持文件上傳，支持自動響應內容的編碼，支持國際化的URL和POST數據自動編碼。git

在python內置模塊的基礎上進行了高度的封裝，從而使得python進行網絡請求時，變得人性化，使用Requests能夠垂手可得的完成瀏覽器可有的任何操做。github

現代，國際化，友好。web

requests會自動實現持久鏈接keep-aliveajax

二、基礎入門

1）導入模塊json

import requests

2）發送請求的簡潔api

　　示例代碼：獲取一個網頁（我的github）瀏覽器

1 import requests
2  
3 r = requests.get('https://github.com/Ranxf')       # 最基本的不帶參數的get請求
4 r1 = requests.get(url='http://dict.baidu.com/s', params={'wd': 'python'})      # 帶參數的get請求
5

咱們就可使用該方式使用如下各類方法

1   requests.get(‘https://github.com/timeline.json’)                                # GET請求
2   requests.post(「http://httpbin.org/post」)                                        # POST請求
3   requests.put(「http://httpbin.org/put」)                                          # PUT請求
4   requests.delete(「http://httpbin.org/delete」)                                    # DELETE請求
5   requests.head(「http://httpbin.org/get」)                                         # HEAD請求
6   requests.options(「http://httpbin.org/get」 )                                     # OPTIONS請求

3）爲url傳遞參數

>>> url_params = {'key':'value'}       #    字典傳遞參數，若是值爲None的鍵不會被添加到url中
>>> r = requests.get('your url',params = url_params)
>>> print(r.url)
　　your url?key=value

4）響應的內容

r.encoding                       #獲取當前的編碼
r.encoding = 'utf-8'             #設置編碼
r.text                           #以encoding解析返回內容。字符串方式的響應體，會自動根據響應頭部的字符編碼進行解碼。
r.content                        #以字節形式（二進制）返回。字節方式的響應體，會自動爲你解碼 gzip 和 deflate 壓縮。

r.headers                        #以字典對象存儲服務器響應頭，可是這個字典比較特殊，字典鍵不區分大小寫，若鍵不存在則返回None

r.status_code                     #響應狀態碼
r.raw                             #返回原始響應體，也就是 urllib 的 response 對象，使用 r.raw.read()   
r.ok                              # 查看r.ok的布爾值即可以知道是否登錄成功
 #*特殊方法*#
r.json()                         #Requests中內置的JSON解碼器，以json形式返回,前提返回的內容確保是json格式的，否則解析出錯會拋異常
r.raise_for_status()             #失敗請求(非200響應)拋出異常

post發送json請求：

1 import requests
2 import json
3  
4 r = requests.post('https://api.github.com/some/endpoint', data=json.dumps({'some': 'data'}))
5 print(r.json())

5）定製頭和cookie信息

header = {'user-agent': 'my-app/0.0.1''}
cookie = {'key':'value'}
 r = requests.get/post('your url',headers=header,cookies=cookie)

import requests
import json
 
data = {'some': 'data'}
headers = {'content-type': 'application/json',
           'User-Agent': 'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:22.0) Gecko/20100101 Firefox/22.0'}
 
r = requests.post('https://api.github.com/some/endpoint', data=data, headers=headers)
print(r.text)

6）響應狀態碼

使用requests方法後，會返回一個response對象，其存儲了服務器響應的內容，如上實例中已經提到的 r.text、r.status_code……
獲取文本方式的響應體實例：當你訪問 r.text 之時，會使用其響應的文本編碼進行解碼，而且你能夠修改其編碼讓 r.text 使用自定義的編碼進行解碼。

1 r = requests.get('http://www.itwhy.org')
2 print(r.text, '\n{}\n'.format('*'*79), r.encoding)
3 r.encoding = 'GBK'
4 print(r.text, '\n{}\n'.format('*'*79), r.encoding)

示例代碼：

1 import requests
2 
3 r = requests.get('https://github.com/Ranxf')       # 最基本的不帶參數的get請求
4 print(r.status_code)                               # 獲取返回狀態
5 r1 = requests.get(url='http://dict.baidu.com/s', params={'wd': 'python'})      # 帶參數的get請求
6 print(r1.url)
7 print(r1.text)        # 打印解碼後的返回數據

運行結果：

/usr/bin/python3.5 /home/rxf/python3_1000/1000/python3_server/python3_requests/demo1.py
200
http://dict.baidu.com/s?wd=python
…………

Process finished with exit code 0

 r.status_code                      #若是不是200，可使用 r.raise_for_status() 拋出異常

7）響應

r.headers                                  #返回字典類型,頭信息
r.requests.headers                         #返回發送到服務器的頭信息
r.cookies                                  #返回cookie
r.history                                  #返回重定向信息,固然能夠在請求是加上allow_redirects = false 阻止重定向

8）超時

r = requests.get('url',timeout=1)           #設置秒數超時，僅對於鏈接有效

9)會話對象，可以跨請求保持某些參數

s = requests.Session()
s.auth = ('auth','passwd')
s.headers = {'key':'value'}
r = s.get('url')
r1 = s.get('url1')

10）代理

proxies = {'http':'ip1','https':'ip2' }
requests.get('url',proxies=proxies)

彙總：

# HTTP請求類型
# get類型
r = requests.get('https://github.com/timeline.json')
# post類型
r = requests.post("http://m.ctrip.com/post")
# put類型
r = requests.put("http://m.ctrip.com/put")
# delete類型
r = requests.delete("http://m.ctrip.com/delete")
# head類型
r = requests.head("http://m.ctrip.com/head")
# options類型
r = requests.options("http://m.ctrip.com/get")

# 獲取響應內容
print(r.content) #以字節的方式去顯示，中文顯示爲字符
print(r.text) #以文本的方式去顯示

#URL傳遞參數
payload = {'keyword': '香港', 'salecityid': '2'}
r = requests.get("http://m.ctrip.com/webapp/tourvisa/visa_list", params=payload) 
print（r.url） #示例爲http://m.ctrip.com/webapp/tourvisa/visa_list?salecityid=2&keyword=香港

#獲取/修改網頁編碼
r = requests.get('https://github.com/timeline.json')
print （r.encoding）


#json處理
r = requests.get('https://github.com/timeline.json')
print（r.json()） # 須要先import json    

# 定製請求頭
url = 'http://m.ctrip.com'
headers = {'User-Agent' : 'Mozilla/5.0 (Linux; Android 4.2.1; en-us; Nexus 4 Build/JOP40D) AppleWebKit/535.19 (KHTML, like Gecko) Chrome/18.0.1025.166 Mobile Safari/535.19'}
r = requests.post(url, headers=headers)
print （r.request.headers)

#複雜post請求
url = 'http://m.ctrip.com' payload = {'some': 'data'} r = requests.post(url, data=json.dumps(payload)) #若是傳遞的payload是string而不是dict，須要先調用dumps方法格式化一下

# post多部分編碼文件
url = 'http://m.ctrip.com'
files = {'file': open('report.xls', 'rb')}
r = requests.post(url, files=files)

# 響應狀態碼
r = requests.get('http://m.ctrip.com')
print(r.status_code)
    
# 響應頭
r = requests.get('http://m.ctrip.com')
print (r.headers)
print (r.headers['Content-Type'])
print (r.headers.get('content-type')) #訪問響應頭部份內容的兩種方式
    
# Cookies
url = 'http://example.com/some/cookie/setting/url'
r = requests.get(url)
r.cookies['example_cookie_name']    #讀取cookies
    
url = 'http://m.ctrip.com/cookies'
cookies = dict(cookies_are='working')
r = requests.get(url, cookies=cookies) #發送cookies

#設置超時時間
r = requests.get('http://m.ctrip.com', timeout=0.001)

#設置訪問代理
proxies = {
           "http": "http://10.10.1.10:3128",
           "https": "http://10.10.1.100:4444",
          }
r = requests.get('http://m.ctrip.com', proxies=proxies)


#若是代理須要用戶名和密碼，則須要這樣：

proxies = { "http": "http://user:pass@10.10.1.10:3128/", }

三、示例代碼

GET請求

1 # 一、無參數實例
 2   
 3 import requests
 4   
 5 ret = requests.get('https://github.com/timeline.json')
 6   
 7 print(ret.url)
 8 print(ret.text)
 9   
10   
11   
12 # 二、有參數實例
13   
14 import requests
15   
16 payload = {'key1': 'value1', 'key2': 'value2'}
17 ret = requests.get("http://httpbin.org/get", params=payload)
18   
19 print(ret.url)
20 print(ret.text)

POST請求

# 一、基本POST實例
  
import requests
  
payload = {'key1': 'value1', 'key2': 'value2'}
ret = requests.post("http://httpbin.org/post", data=payload)
  
print(ret.text)
  
  
# 二、發送請求頭和數據實例
  
import requests
import json
  
url = 'https://api.github.com/some/endpoint'
payload = {'some': 'data'}
headers = {'content-type': 'application/json'}
  
ret = requests.post(url, data=json.dumps(payload), headers=headers)
  
print(ret.text)
print(ret.cookies)

請求參數

 1 def request(method, url, **kwargs):
 2     """Constructs and sends a :class:`Request <Request>`.
 3 
 4     :param method: method for the new :class:`Request` object.
 5     :param url: URL for the new :class:`Request` object.
 6     :param params: (optional) Dictionary or bytes to be sent in the query string for the :class:`Request`.
 7     :param data: (optional) Dictionary, bytes, or file-like object to send in the body of the :class:`Request`.
 8     :param json: (optional) json data to send in the body of the :class:`Request`.
 9     :param headers: (optional) Dictionary of HTTP Headers to send with the :class:`Request`.
10     :param cookies: (optional) Dict or CookieJar object to send with the :class:`Request`.
11     :param files: (optional) Dictionary of ``'name': file-like-objects`` (or ``{'name': file-tuple}``) for multipart encoding upload.
12         ``file-tuple`` can be a 2-tuple ``('filename', fileobj)``, 3-tuple ``('filename', fileobj, 'content_type')``
13         or a 4-tuple ``('filename', fileobj, 'content_type', custom_headers)``, where ``'content-type'`` is a string
14         defining the content type of the given file and ``custom_headers`` a dict-like object containing additional headers
15         to add for the file.
16     :param auth: (optional) Auth tuple to enable Basic/Digest/Custom HTTP Auth.
17     :param timeout: (optional) How long to wait for the server to send data
18         before giving up, as a float, or a :ref:`(connect timeout, read
19         timeout) <timeouts>` tuple.
20     :type timeout: float or tuple
21     :param allow_redirects: (optional) Boolean. Set to True if POST/PUT/DELETE redirect following is allowed.
22     :type allow_redirects: bool
23     :param proxies: (optional) Dictionary mapping protocol to the URL of the proxy.
24     :param verify: (optional) whether the SSL cert will be verified. A CA_BUNDLE path can also be provided. Defaults to ``True``.
25     :param stream: (optional) if ``False``, the response content will be immediately downloaded.
26     :param cert: (optional) if String, path to ssl client cert file (.pem). If Tuple, ('cert', 'key') pair.
27     :return: :class:`Response <Response>` object
28     :rtype: requests.Response
29 
30     Usage::
31 
32       >>> import requests
33       >>> req = requests.request('GET', 'http://httpbin.org/get')
34       <Response [200]>
35     """
36 
37 參數列表

請求參數

def param_method_url():
    # requests.request(method='get', url='http://127.0.0.1:8000/test/')
    # requests.request(method='post', url='http://127.0.0.1:8000/test/')
    pass


def param_param():
    # - 能夠是字典
    # - 能夠是字符串
    # - 能夠是字節（ascii編碼之內）

    # requests.request(method='get',
    # url='http://127.0.0.1:8000/test/',
    # params={'k1': 'v1', 'k2': '水電費'})

    # requests.request(method='get',
    # url='http://127.0.0.1:8000/test/',
    # params="k1=v1&k2=水電費&k3=v3&k3=vv3")

    # requests.request(method='get',
    # url='http://127.0.0.1:8000/test/',
    # params=bytes("k1=v1&k2=k2&k3=v3&k3=vv3", encoding='utf8'))

    # 錯誤
    # requests.request(method='get',
    # url='http://127.0.0.1:8000/test/',
    # params=bytes("k1=v1&k2=水電費&k3=v3&k3=vv3", encoding='utf8'))
    pass


def param_data():
    # 能夠是字典
    # 能夠是字符串
    # 能夠是字節
    # 能夠是文件對象

    # requests.request(method='POST',
    # url='http://127.0.0.1:8000/test/',
    # data={'k1': 'v1', 'k2': '水電費'})

    # requests.request(method='POST',
    # url='http://127.0.0.1:8000/test/',
    # data="k1=v1; k2=v2; k3=v3; k3=v4"
    # )

    # requests.request(method='POST',
    # url='http://127.0.0.1:8000/test/',
    # data="k1=v1;k2=v2;k3=v3;k3=v4",
    # headers={'Content-Type': 'application/x-www-form-urlencoded'}
    # )

    # requests.request(method='POST',
    # url='http://127.0.0.1:8000/test/',
    # data=open('data_file.py', mode='r', encoding='utf-8'), # 文件內容是：k1=v1;k2=v2;k3=v3;k3=v4
    # headers={'Content-Type': 'application/x-www-form-urlencoded'}
    # )
    pass


def param_json():
    # 將json中對應的數據進行序列化成一個字符串，json.dumps(...)
    # 而後發送到服務器端的body中，而且Content-Type是 {'Content-Type': 'application/json'}
    requests.request(method='POST',
                     url='http://127.0.0.1:8000/test/',
                     json={'k1': 'v1', 'k2': '水電費'})


def param_headers():
    # 發送請求頭到服務器端
    requests.request(method='POST',
                     url='http://127.0.0.1:8000/test/',
                     json={'k1': 'v1', 'k2': '水電費'},
                     headers={'Content-Type': 'application/x-www-form-urlencoded'}
                     )


def param_cookies():
    # 發送Cookie到服務器端
    requests.request(method='POST',
                     url='http://127.0.0.1:8000/test/',
                     data={'k1': 'v1', 'k2': 'v2'},
                     cookies={'cook1': 'value1'},
                     )
    # 也可使用CookieJar（字典形式就是在此基礎上封裝）
    from http.cookiejar import CookieJar
    from http.cookiejar import Cookie

    obj = CookieJar()
    obj.set_cookie(Cookie(version=0, name='c1', value='v1', port=None, domain='', path='/', secure=False, expires=None,
                          discard=True, comment=None, comment_url=None, rest={'HttpOnly': None}, rfc2109=False,
                          port_specified=False, domain_specified=False, domain_initial_dot=False, path_specified=False)
                   )
    requests.request(method='POST',
                     url='http://127.0.0.1:8000/test/',
                     data={'k1': 'v1', 'k2': 'v2'},
                     cookies=obj)


def param_files():
    # 發送文件
    # file_dict = {
    # 'f1': open('readme', 'rb')
    # }
    # requests.request(method='POST',
    # url='http://127.0.0.1:8000/test/',
    # files=file_dict)

    # 發送文件，定製文件名
    # file_dict = {
    # 'f1': ('test.txt', open('readme', 'rb'))
    # }
    # requests.request(method='POST',
    # url='http://127.0.0.1:8000/test/',
    # files=file_dict)

    # 發送文件，定製文件名
    # file_dict = {
    # 'f1': ('test.txt', "hahsfaksfa9kasdjflaksdjf")
    # }
    # requests.request(method='POST',
    # url='http://127.0.0.1:8000/test/',
    # files=file_dict)

    # 發送文件，定製文件名
    # file_dict = {
    #     'f1': ('test.txt', "hahsfaksfa9kasdjflaksdjf", 'application/text', {'k1': '0'})
    # }
    # requests.request(method='POST',
    #                  url='http://127.0.0.1:8000/test/',
    #                  files=file_dict)

    pass


def param_auth():
    from requests.auth import HTTPBasicAuth, HTTPDigestAuth

    ret = requests.get('https://api.github.com/user', auth=HTTPBasicAuth('wupeiqi', 'sdfasdfasdf'))
    print(ret.text)

    # ret = requests.get('http://192.168.1.1',
    # auth=HTTPBasicAuth('admin', 'admin'))
    # ret.encoding = 'gbk'
    # print(ret.text)

    # ret = requests.get('http://httpbin.org/digest-auth/auth/user/pass', auth=HTTPDigestAuth('user', 'pass'))
    # print(ret)
    #


def param_timeout():
    # ret = requests.get('http://google.com/', timeout=1)
    # print(ret)

    # ret = requests.get('http://google.com/', timeout=(5, 1))
    # print(ret)
    pass


def param_allow_redirects():
    ret = requests.get('http://127.0.0.1:8000/test/', allow_redirects=False)
    print(ret.text)


def param_proxies():
    # proxies = {
    # "http": "61.172.249.96:80",
    # "https": "http://61.185.219.126:3128",
    # }

    # proxies = {'http://10.20.1.128': 'http://10.10.1.10:5323'}

    # ret = requests.get("http://www.proxy360.cn/Proxy", proxies=proxies)
    # print(ret.headers)


    # from requests.auth import HTTPProxyAuth
    #
    # proxyDict = {
    # 'http': '77.75.105.165',
    # 'https': '77.75.105.165'
    # }
    # auth = HTTPProxyAuth('username', 'mypassword')
    #
    # r = requests.get("http://www.google.com", proxies=proxyDict, auth=auth)
    # print(r.text)

    pass


def param_stream():
    ret = requests.get('http://127.0.0.1:8000/test/', stream=True)
    print(ret.content)
    ret.close()

    # from contextlib import closing
    # with closing(requests.get('http://httpbin.org/get', stream=True)) as r:
    # # 在此處理響應。
    # for i in r.iter_content():
    # print(i)


def requests_session():
    import requests

    session = requests.Session()

    ### 一、首先登錄任何頁面，獲取cookie

    i1 = session.get(url="http://dig.chouti.com/help/service")

    ### 二、用戶登錄，攜帶上一次的cookie，後臺對cookie中的 gpsd 進行受權
    i2 = session.post(
        url="http://dig.chouti.com/login",
        data={
            'phone': "8615131255089",
            'password': "xxxxxx",
            'oneMonth': ""
        }
    )

    i3 = session.post(
        url="http://dig.chouti.com/link/vote?linksId=8589623",
    )
    print(i3.text)

參數示例

參數示例代碼

json請求：

 1 #! /usr/bin/python3
 2 import requests
 3 import json
 4 
 5 
 6 class url_request():
 7     def __init__(self):
 8         ''' init '''
 9 
10 if __name__ == '__main__':
11     heard = {'Content-Type': 'application/json'}
12     payload = {'CountryName': '中國',
13                'ProvinceName': '四川省',
14                'L1CityName': 'chengdu',
15                'L2CityName': 'yibing',
16                'TownName': '',
17                'Longitude': '107.33393',
18                'Latitude': '33.157131',
19                'Language': 'CN'}
20     r = requests.post("http://www.xxxxxx.com/CityLocation/json/LBSLocateCity", heards=heard, data=payload)
21     data = r.json()
22     if r.status_code!=200:
23         print('LBSLocateCity API Error' + str(r.status_code))
24     print(data['CityEntities'][0]['CityID'])  # 打印返回json中的某個key的value
25     print(data['ResponseStatus']['Ack'])
26     print(json.dump(data, indent=4, sort_keys=True, ensure_ascii=False))  # 樹形打印json，ensure_ascii必須設爲False不然中文會顯示爲unicode

Xml請求：

 1 #! /usr/bin/python3
 2 import requests
 3 
 4 class url_request():
 5     def __init__(self):
 6         """init"""
 7 
 8 if __name__ == '__main__':
 9     heards = {'Content-type': 'text/xml'}
10     XML = '<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"><soap:Body><Request xmlns="http://tempuri.org/"><jme><JobClassFullName>WeChatJSTicket.JobWS.Job.JobRefreshTicket,WeChatJSTicket.JobWS</JobClassFullName><Action>RUN</Action><Param>1</Param><HostIP>127.0.0.1</HostIP><JobInfo>1</JobInfo><NeedParallel>false</NeedParallel></jme></Request></soap:Body></soap:Envelope>'
11     url = 'http://jobws.push.mobile.xxxxxxxx.com/RefreshWeiXInTokenJob/RefreshService.asmx'
12     r = requests.post(url=url, heards=heards, data=XML)
13     data = r.text
14     print(data)

狀態異常處理

 1 import requests
 2 
 3 URL = 'http://ip.taobao.com/service/getIpInfo.php'  # 淘寶IP地址庫API
 4 try:
 5     r = requests.get(URL, params={'ip': '8.8.8.8'}, timeout=1)
 6     r.raise_for_status()  # 若是響應狀態碼不是 200，就主動拋出異常
 7 except requests.RequestException as e:
 8     print(e)
 9 else:
10     result = r.json()
11     print(type(result), result, sep='\n')

上傳文件

使用request模塊，也能夠上傳文件，文件的類型會自動進行處理：

import requests
 
url = 'http://127.0.0.1:8080/upload'
files = {'file': open('/home/rxf/test.jpg', 'rb')}
#files = {'file': ('report.jpg', open('/home/lyb/sjzl.mpg', 'rb'))}     #顯式的設置文件名
 
r = requests.post(url, files=files)
print(r.text)

request更加方便的是，能夠把字符串看成文件進行上傳：

import requests
 
url = 'http://127.0.0.1:8080/upload'
files = {'file': ('test.txt', b'Hello Requests.')}     #必需顯式的設置文件名
 
r = requests.post(url, files=files)
print(r.text)

6) 身份驗證

基自己份認證(HTTP Basic Auth)

import requests
from requests.auth import HTTPBasicAuth
 
r = requests.get('https://httpbin.org/hidden-basic-auth/user/passwd', auth=HTTPBasicAuth('user', 'passwd'))
# r = requests.get('https://httpbin.org/hidden-basic-auth/user/passwd', auth=('user', 'passwd'))    # 簡寫
print(r.json())

另外一種很是流行的HTTP身份認證形式是摘要式身份認證，Requests對它的支持也是開箱便可用的:

requests.get(URL, auth=HTTPDigestAuth('user', 'pass'))

Cookies與會話對象

若是某個響應中包含一些Cookie，你能夠快速訪問它們：

import requests
 
r = requests.get('http://www.google.com.hk/')
print(r.cookies['NID'])
print(tuple(r.cookies))

要想發送你的cookies到服務器，可使用 cookies 參數：

import requests
 
url = 'http://httpbin.org/cookies'
cookies = {'testCookies_1': 'Hello_Python3', 'testCookies_2': 'Hello_Requests'}
# 在Cookie Version 0中規定空格、方括號、圓括號、等於號、逗號、雙引號、斜槓、問號、@，冒號，分號等特殊符號都不能做爲Cookie的內容。
r = requests.get(url, cookies=cookies)
print(r.json())

會話對象讓你可以跨請求保持某些參數，最方便的是在同一個Session實例發出的全部請求之間保持cookies，且這些都是自動處理的，甚是方便。
下面就來一個真正的實例，以下是快盤簽到腳本：

import requests
 
headers = {'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
           'Accept-Encoding': 'gzip, deflate, compress',
           'Accept-Language': 'en-us;q=0.5,en;q=0.3',
           'Cache-Control': 'max-age=0',
           'Connection': 'keep-alive',
           'User-Agent': 'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:22.0) Gecko/20100101 Firefox/22.0'}
 
s = requests.Session()
s.headers.update(headers)
# s.auth = ('superuser', '123')
s.get('https://www.kuaipan.cn/account_login.htm')
 
_URL = 'http://www.kuaipan.cn/index.php'
s.post(_URL, params={'ac':'account', 'op':'login'},
       data={'username':'****@foxmail.com', 'userpwd':'********', 'isajax':'yes'})
r = s.get(_URL, params={'ac':'zone', 'op':'taskdetail'})
print(r.json())
s.get(_URL, params={'ac':'common', 'op':'usersign'})

requests模塊抓取網頁源碼並保存到文件示例

這是一個基本的文件保存操做，但這裏有幾個值得注意的問題：

1.安裝requests包，命令行輸入pip install requests便可自動安裝。不少人推薦使用requests，自帶的urllib.request也能夠抓取網頁源碼

2.open方法encoding參數設爲utf-8，不然保存的文件會出現亂碼。

3.若是直接在cmd中輸出抓取的內容，會提示各類編碼錯誤，因此保存到文件查看。

4.with open方法是更好的寫法，能夠自動操做完畢後釋放資源。

#! /urs/bin/python3
import requests

'''requests模塊抓取網頁源碼並保存到文件示例'''
html = requests.get("http://www.baidu.com")
with open('test.txt', 'w', encoding='utf-8') as f:
    f.write(html.text)
    
'''讀取一個txt文件，每次讀取一行，並保存到另外一個txt文件中的示例'''
ff = open('testt.txt', 'w', encoding='utf-8')
with open('test.txt', encoding="utf-8") as f:
    for line in f:
        ff.write(line)
        ff.close()

由於在命令行中打印每次讀取一行的數據，中文會出現編碼錯誤，因此每次讀取一行並保存到另外一個文件，這樣來測試讀取是否正常。（注意open的時候制定encoding編碼方式）

自動登陸示例：

 import requests
 2 from bs4 import BeautifulSoup
 3 
 4 
 5 def login_github():
 6     """
 7     經過requests模塊模擬瀏覽器登錄GitHub
 8     :return: 
 9     """
10     # 獲取csrf_token
11     r1 = requests.get('https://github.com/login')   # 得到get請求的對象
12     s1 = BeautifulSoup(r1.text, 'html.parser')      # 使用bs4解析HTML對象
13     token = s1.find('input', attrs={'name': 'authenticity_token'}).get('value')     # 獲取登錄受權碼，即csrf_token
14     get_cookies = r1.cookies.get_dict()     # 獲取get請求的cookies，post請求時必須攜帶
15     
16     # 發送post登錄請求
17     '''
18     post登錄參數
19     commit    Sign+in
20     utf8    ✓
21     authenticity_token    E961jQMIyC9NPwL54YPj70gv2hbXWJ…fTUd+e4lT5RAizKbfzQo4eRHsfg==
22     login    JackUpDown（用戶名）
23     password    **********（密碼）
24     '''
25     r2 = requests.post(
26         'https://github.com/session',
27         data={
28             'commit': 'Sign+in',
29             'utf8': '✓',
30             'authenticity_token': token,
31             'login': 'JackUpDown',
32             'password': '**********'
33         },
34         cookies=get_cookies     # 攜帶get請求的cookies
35                        )
36     login_cookies = r2.cookies.get_dict()   # 得到登錄成功的cookies，攜帶此cookies就能夠訪問任意GitHub頁面
37 
38     # 攜帶post cookies跳轉任意頁面
39     r3 = requests.get('https://github.com/settings/emails', cookies=login_cookies)
40     print(r3.text)

requests模擬登錄GitHub

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import requests


# ############## 方式一 ##############
"""
# ## 一、首先登錄任何頁面，獲取cookie
i1 = requests.get(url="http://dig.chouti.com/help/service")
i1_cookies = i1.cookies.get_dict()

# ## 二、用戶登錄，攜帶上一次的cookie，後臺對cookie中的 gpsd 進行受權
i2 = requests.post(
    url="http://dig.chouti.com/login",
    data={
        'phone': "8615131255089",
        'password': "xxooxxoo",
        'oneMonth': ""
    },
    cookies=i1_cookies
)

# ## 三、點贊（只須要攜帶已經被受權的gpsd便可）
gpsd = i1_cookies['gpsd']
i3 = requests.post(
    url="http://dig.chouti.com/link/vote?linksId=8589523",
    cookies={'gpsd': gpsd}
)

print(i3.text)
"""


# ############## 方式二 ##############
"""
import requests

session = requests.Session()
i1 = session.get(url="http://dig.chouti.com/help/service")
i2 = session.post(
    url="http://dig.chouti.com/login",
    data={
        'phone': "8615131255089",
        'password': "xxooxxoo",
        'oneMonth': ""
    }
)
i3 = session.post(
    url="http://dig.chouti.com/link/vote?linksId=8589523"
)
print(i3.text)

"""

抽屜新熱榜

熱搜新聞榜

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import time

import requests
from bs4 import BeautifulSoup

session = requests.Session()

i1 = session.get(
    url='https://www.zhihu.com/#signin',
    headers={
        'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36',
    }
)

soup1 = BeautifulSoup(i1.text, 'lxml')
xsrf_tag = soup1.find(name='input', attrs={'name': '_xsrf'})
xsrf = xsrf_tag.get('value')

current_time = time.time()
i2 = session.get(
    url='https://www.zhihu.com/captcha.gif',
    params={'r': current_time, 'type': 'login'},
    headers={
        'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36',
    })

with open('zhihu.gif', 'wb') as f:
    f.write(i2.content)

captcha = input('請打開zhihu.gif文件，查看並輸入驗證碼：')
form_data = {
    "_xsrf": xsrf,
    'password': 'xxooxxoo',
    "captcha": 'captcha',
    'email': '424662508@qq.com'
}
i3 = session.post(
    url='https://www.zhihu.com/login/email',
    data=form_data,
    headers={
        'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36',
    }
)

i4 = session.get(
    url='https://www.zhihu.com/settings/profile',
    headers={
        'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36',
    }
)

soup4 = BeautifulSoup(i4.text, 'lxml')
tag = soup4.find(id='rename-section')
nick_name = tag.find('span',class_='name').string
print(nick_name)

知乎

知乎

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import re
import json
import base64

import rsa
import requests


def js_encrypt(text):
    b64der = 'MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCp0wHYbg/NOPO3nzMD3dndwS0MccuMeXCHgVlGOoYyFwLdS24Im2e7YyhB0wrUsyYf0/nhzCzBK8ZC9eCWqd0aHbdgOQT6CuFQBMjbyGYvlVYU2ZP7kG9Ft6YV6oc9ambuO7nPZh+bvXH0zDKfi02prknrScAKC0XhadTHT3Al0QIDAQAB'
    der = base64.standard_b64decode(b64der)

    pk = rsa.PublicKey.load_pkcs1_openssl_der(der)
    v1 = rsa.encrypt(bytes(text, 'utf8'), pk)
    value = base64.encodebytes(v1).replace(b'\n', b'')
    value = value.decode('utf8')

    return value


session = requests.Session()

i1 = session.get('https://passport.cnblogs.com/user/signin')
rep = re.compile("'VerificationToken': '(.*)'")
v = re.search(rep, i1.text)
verification_token = v.group(1)

form_data = {
    'input1': js_encrypt('wptawy'),
    'input2': js_encrypt('asdfasdf'),
    'remember': False
}

i2 = session.post(url='https://passport.cnblogs.com/user/signin',
                  data=json.dumps(form_data),
                  headers={
                      'Content-Type': 'application/json; charset=UTF-8',
                      'X-Requested-With': 'XMLHttpRequest',
                      'VerificationToken': verification_token}
                  )

i3 = session.get(url='https://i.cnblogs.com/EditDiary.aspx')

print(i3.text)