一：什么是Requests
Requests是用python语言基于urllib编写的，采用的是Apache2 Licensed开源协议的HTTP库
如果你看过上篇文章关于urllib库的使用，你会发现，其实urllib还是非常不方便的，而Requests它会比urllib更加方便，可以节约我们大量的工作。（用了requests之后，你基本都不愿意用urllib了）一句话，requests是python实现的最简单易用的HTTP库，建议爬虫使用requests库。
默认安装好python之后，是没有安装requests模块的，需要单独通过pip安装
二：Requests功能详解
实例引入：
import requests response = requests.get('https://www.baidu.com/') # 添加编码方式，解决乱码问题 response.encoding=response.apparent_encoding
# response.encoding="utf-8"
print(type(response))
print(response.status_code) # 状态码
print(type(response.text))
print(response.text) # 响应的文本内容
print(response.cookies) # 响应的cookie
各种请求方式：
import requests requests.get('https://www.baidu.com/') # get requests.post('http://httpbin.org/post') # post requests.put('http://httpbin.org/put') requests.delete('http://httpbin.org/delete') requests.head('http://httpbin.org/get') requests.options('http://httpbin.org/get')
请求
基本GET请求
import requests response = requests.get('http://httpbin.org/get') print(response.text)
带参数的GET请求
# 方式一 import requests # 直接加在url后面 response = requests.get("http://httpbin.org/get?name=germey&age=22") print(response.text) # 方式二 import requests data = { 'name': 'germey', 'age': 22 } # 通过params来传递data response = requests.get("http://httpbin.org/get", params=data) print(response.text) # 上述两种的结果是相同的，通过params参数传递一个字典内容，从而直接构造url # 注意：第二种方式通过字典的方式的时候，如果字典中的参数为None则不会添加到url上
解析json
import requests import json response = requests.get("http://httpbin.org/get") print(type(response.text)) print(response.json()) # 实际上是执行了json.loads(response.text) print(json.loads(response.text)) print(type(response.json()))
获取二进制数据
import requests # 获取并打印二进制数据 response = requests.get("https://github.com/favicon.ico") print(type(response.text), type(response.content)) print(response.text) print(response.content) # 获取二进制数据并存入文件，通常如视频，图片，音乐等 response = requests.get("https://github.com/favicon.ico") with open('favicon.ico', 'wb') as f: f.write(response.content) f.close()
添加headers
# 有些网站必须要带头部信息才能正常访问 import requests headers = { 'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36' } response = requests.get("https://www.zhihu.com/explore", headers=headers) print(response.text)
基本POST请求
import requests data = {'name': 'germey', 'age': '22'} # 通过字典类型构造 response = requests.post("http://httpbin.org/post", data=data) print(response.text)
响应
reponse属性
import requests response = requests.get('http://www.jianshu.com') print(type(response.status_code), response.status_code) # 状态码 print(type(response.headers), response.headers) # 头信息 print(type(response.cookies), response.cookies) # cookies print(type(response.url), response.url) # url print(type(response.history), response.history) # 访问列表
状态码判断：--》状态码大全
100: ('continue',), 101: ('switching_protocols',), 102: ('processing',), 103: ('checkpoint',), 122: ('uri_too_long', 'request_uri_too_long'), 200: ('ok', 'okay', 'all_ok', 'all_okay', 'all_good', '\o/', '✓'), 201: ('created',), 202: ('accepted',), 203: ('non_authoritative_info', 'non_authoritative_information'), 204: ('no_content',), 205: ('reset_content', 'reset'), 206: ('partial_content', 'partial'), 207: ('multi_status', 'multiple_status', 'multi_stati', 'multiple_stati'), 208: ('already_reported',), 226: ('im_used',), # Redirection. 300: ('multiple_choices',), 301: ('moved_permanently', 'moved', '\o-'), 302: ('found',), 303: ('see_other', 'other'), 304: ('not_modified',), 305: ('use_proxy',), 306: ('switch_proxy',), 307: ('temporary_redirect', 'temporary_moved', 'temporary'), 308: ('permanent_redirect', 'resume_incomplete', 'resume',), # These 2 to be removed in 3.0 # Client Error. 400: ('bad_request', 'bad'), 401: ('unauthorized',), 402: ('payment_required', 'payment'), 403: ('forbidden',), 404: ('not_found', '-o-'), 405: ('method_not_allowed', 'not_allowed'), 406: ('not_acceptable',), 407: ('proxy_authentication_required', 'proxy_auth', 'proxy_authentication'), 408: ('request_timeout', 'timeout'), 409: ('conflict',), 410: ('gone',), 411: ('length_required',), 412: ('precondition_failed', 'precondition'), 413: ('request_entity_too_large',), 414: ('request_uri_too_large',), 415: ('unsupported_media_type', 'unsupported_media', 'media_type'), 416: ('requested_range_not_satisfiable', 'requested_range', 'range_not_satisfiable'), 417: ('expectation_failed',), 418: ('im_a_teapot', 'teapot', 'i_am_a_teapot'), 421: ('misdirected_request',), 422: ('unprocessable_entity', 'unprocessable'), 423: ('locked',), 424: ('failed_dependency', 'dependency'), 425: ('unordered_collection', 'unordered'), 426: ('upgrade_required', 'upgrade'), 428: ('precondition_required', 'precondition'), 429: ('too_many_requests', 'too_many'), 431: ('header_fields_too_large', 'fields_too_large'), 444: ('no_response', 'none'), 449: ('retry_with', 'retry'), 450: ('blocked_by_windows_parental_controls', 'parental_controls'), 451: ('unavailable_for_legal_reasons', 'legal_reasons'), 499: ('client_closed_request',), # Server Error. 500: ('internal_server_error', 'server_error', '/o\', '✗'), 501: ('not_implemented',), 502: ('bad_gateway',), 503: ('service_unavailable', 'unavailable'), 504: ('gateway_timeout',), 505: ('http_version_not_supported', 'http_version'), 506: ('variant_also_negotiates',), 507: ('insufficient_storage',), 509: ('bandwidth_limit_exceeded', 'bandwidth'), 510: ('not_extended',), 511: ('network_authentication_required', 'network_auth', 'network_authentication'),
三：requests高级操作
文件上传
import requests # 通过files参数上传，必须以二进制读取 files = {'file': open('favicon.ico', 'rb')} response = requests.post("http://httpbin.org/post", files=files) print(response.text)
获取cookie
import requests response = requests.get("https://www.baidu.com") print(response.cookies) for key, value in response.cookies.items(): print(key + '=' + value)
会话维持
# cookie的一个作用就是可以用于模拟登陆，做会话维持 import requests s = requests.Session() # 通过session对象来维持cookie s.get('http://httpbin.org/cookies/set/number/123456789') response = s.get('http://httpbin.org/cookies') print(response.text)
证书验证
# 现在的很多网站都是https的方式访问，所以这个时候就涉及到证书的问题 import requests from requests.packages import urllib3 urllib3.disable_warnings() # 取消警告（可以不要） # 取消证书验证，默认是验证证书，如果证书不合法会报错 response = requests.get('https://www.12306.cn', verify=False) print(response.status_code)
代理设置
import requests proxies = { "http": "http://127.0.0.1:9743", "https": "https://127.0.0.1:9743", } # 通过proxies来设置代理 response = requests.get("https://www.taobao.com", proxies=proxies) print(response.status_code) ‘‘‘ # 如果代理需要设置用户名和密码，则将字典改写成 proxies = { "http":"http://user:password@127.0.0.1:9999" } # 如果代理是通过sokces这种方式，则需要： pip install "requests[socks]" # 安装模块 proxies= { "http":"socks5://127.0.0.1:9999", "https":"sockes5://127.0.0.1:8888" } ’’’
超时设置
import requests from requests.exceptions import ReadTimeout try: # 通过timeout参数设置超时的时间 response = requests.get("http://httpbin.org/get", timeout = 0.5) print(response.status_code) except ReadTimeout: print('Timeout')
认证设置
# 如果碰到需要认证的网站可以通过requests.auth模块实现 # 方式一 import requests from requests.auth import HTTPBasicAuth r = requests.get('http://120.27.34.24:9001', auth=HTTPBasicAuth('user', '123')) print(r.status_code) # 方式二 import requests r = requests.get('http://120.27.34.24:9001', auth=('user', '123')) print(r.status_code)
import requests from requests.exceptions import ReadTimeout, ConnectionError, RequestException try: response = requests.get("http://httpbin.org/get", timeout = 0.5) print(response.status_code) except ReadTimeout: print('Timeout') except ConnectionError: print('Connection error') except RequestException: print('Error')