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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,Requests它会比urllib更加方便,可以节约我们大量的工作。

pip快速安装

pip install requests
response  = requests.get("https://www.baidu.com")
print(type(response))
print(response.status_code)
print(type(response.text))
response.enconding = "utf-8'
print(response.text)
print(response.cookies)
print(response.content)
print(response.content.decode("utf-8"))

  response.text返回的是Unicode格式,通常需要转换为utf-8格式,否则就是乱码。response.content是二进制模式,可以下载视频之类的,如果想看的话需要decode成utf-8格式。
  不管是通过response.content.decode("utf-8)的方式还是通过response.encoding="utf-8"的方式都可以避免乱码的问题发生

  2、一大推请求方式

import requests
requests.post("http://httpbin.org/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")

  带参数的GET请求:

  如果想查询http://httpbin.org/get页面的具体参数,需要在url里面加上,例如我想看有没有Host=httpbin.org这条数据,url形式应该是http://httpbin.org/get?Host=httpbin.org

  下面提交的数据是往这个地址传送data里面的数据。

import requests
url = 'http://httpbin.org/get'
data = {
    'name':'zhangsan',
    'age':'25'
response = requests.get(url,params=data)
print(response.url)
print(response.text)

  Json数据:

  从下面的数据中我们可以得出,如果结果:

  1、requests中response.json()方法等同于json.loads(response.text)方法

import requests
import json
response = requests.get("http://httpbin.org/get")
print(type(response.text))
print(response.json())
print(json.loads(response.text))
print(type(response.json())

  获取二进制数据

  在上面提到了response.content,这样获取的数据是二进制数据,同样的这个方法也可以用于下载图片以及
  视频资源

  添加header

  首先说,为什么要加header(头部信息)呢?例如下面,我们试图访问知乎的登录页面(当然大家都你要是不登录知乎,就看不到里面的内容),我们试试不加header信息会报什么错。

import requests
url = 'https://www.zhihu.com/'
response = requests.get(url)
response.encoding = "utf-8"
print(response.text)

  提示发生内部服务器错误(也就说你连知乎登录页面的html都下载不下来)。

<html><body><h1>500 Server Error</h1>
An internal server error occured.
</body></html>

  如果想访问就必须得加headers信息。

import requests
url = 'https://www.zhihu.com/'
headers = {
    'User-Agent':'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36'
response = requests.get(url,headers=headers)
print(response.text)

   基本post请求:

  通过post把数据提交到url地址,等同于一字典的形式提交form表单里面的数据

import requests
url = 'http://httpbin.org/post'
data = {
    'name':'jack',
    'age':'23'
response = requests.post(url,data=data)
print(response.text)
  "args": {}, 
  "data": "", 
  "files": {}, 
  "form": {
    "age": "23", 
    "name": "jack"
  "headers": {
    "Accept": "*/*", 
    "Accept-Encoding": "gzip, deflate", 
    "Connection": "close", 
    "Content-Length": "16", 
    "Content-Type": "application/x-www-form-urlencoded", 
    "Host": "httpbin.org", 
    "User-Agent": "python-requests/2.13.0"
  "json": null, 
  "origin": "118.144.137.95", 
  "url": "http://httpbin.org/post"
import requests
response = requests.get("http://www.baidu.com")
#打印请求页面的状态(状态码)
print(type(response.status_code),response.status_code)
#打印请求网址的headers所有信息
print(type(response.headers),response.headers)
#打印请求网址的cookies信息
print(type(response.cookies),response.cookies)
#打印请求网址的地址
print(type(response.url),response.url)
#打印请求的历史记录(以列表的形式显示)
print(type(response.history),response.history)

  内置的状态码:

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'),
内置的状态码
import requests
response = requests.get('http://www.jianshu.com/404.html')
# 使用request内置的字母判断状态码
#如果response返回的状态码是非正常的就返回404错误
if response.status_code != requests.codes.ok:
    print('404')
#如果页面返回的状态码是200,就打印下面的状态
response = requests.get('http://www.jianshu.com')
if response.status_code == 200:
    print('200')
url = "http://httpbin.org/post"
files= {"files":open("test.jpg","rb")}
response = requests.post(url,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)

  cookie的一个作用就是可以用于模拟登陆,做会话维持

import requests
session = requests.session()
session.get('http://httpbin.org/cookies/set/number/12456')
response = session.get('http://httpbin.org/cookies')
print(response.text)
import requests
response = requests.get('https://www.12306.cn')
# 在请求https时,request会进行证书的验证,如果验证失败则会抛出异常
print(response.status_code)
import requests
# 关闭验证,但是仍然会报出证书警告
response = requests.get('https://www.12306.cn',verify=False)
print(response.status_code)

  为了避免这种情况的发生可以通过verify=False,但是这样是可以访问到页面结果

   消除验证证书的警报

from requests.packages import urllib3
import requests
urllib3.disable_warnings()
response = requests.get('https://www.12306.cn',verify=False)
print(response.status_code)

  手动设置证书

import requests
response = requests.get('https://www.12306.cn', cert=('/path/server.crt', '/path/key'))
print(response.status_code)

   1、设置普通代理

import requests
proxies = {
  "http": "http://127.0.0.1:9743",
  "https": "https://127.0.0.1:9743",
response = requests.get("https://www.taobao.com", proxies=proxies)
print(response.status_code)

  2、设置用户名和密码代理

import requests
proxies = {
    "http": "http://user:password@127.0.0.1:9743/",
response = requests.get("https://www.taobao.com", proxies=proxies)
print(response.status_code)

  设置socks代理

安装socks模块 pip3 install 'requests[socks]'
import requests
proxies = {
    'http': 'socks5://127.0.0.1:9742',
    'https': 'socks5://127.0.0.1:9742'
response = requests.get("https://www.taobao.com", proxies=proxies)
print(response.status_code)

      通过timeout参数可以设置超时的时间

import requests
from requests.exceptions import ReadTimeout
    # 设置必须在500ms内收到响应,不然或抛出ReadTimeout异常
    response = requests.get("http://httpbin.org/get", timeout=0.5)
    print(response.status_code)
except ReadTimeout:
    print('Timeout')

  如果碰到需要认证的网站可以通过requests.auth模块实现  

import requests
from requests.auth import HTTPBasicAuth
r = requests.get('http://120.27.34.24:9001', auth=HTTPBasicAuth('user', '123'))
#方法二
r = requests.get('http://120.27.34.24:9001', auth=('user', '123')) print(r.status_code)

  关于reqeusts的异常在这里可以看到详细内容:
      http://www.python-requests.org/en/master/api/#exceptions
  所有的异常都是在requests.excepitons中

  从源码我们可以看出RequestException继承IOError,
  HTTPError,ConnectionError,Timeout继承RequestionException
  ProxyError,SSLError继承ConnectionError
  ReadTimeout继承Timeout异常
  这里列举了一些常用的异常继承关系,详细的可以看:
      http://cn.python-requests.org/zh_CN/latest/_modules/requests/exceptions.html#RequestException

  通过下面的例子进行简单的演示

import requests
from requests.exceptions import ReadTimeout, ConnectionError, RequestException
    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')

  首先被捕捉的异常是timeout,当把网络断掉的haul就会捕捉到ConnectionError,如果前面异常都没有捕捉到,最后也可以通过RequestExctption捕捉到