python中requests库使用方法详解,,一、什么是Reque


一、什么是Requests

Requests 是?技术分享图片ython语?编写,基于urllib,采?Apache2 Licensed开源协议的 HTTP 库。它? urllib 更加?便,
可以节约我们?量的?作,完全满?HTTP测试需求。

?句话——Python实现的简单易?的HTTP库

二、安装Requests库

进入命令行win+R执行

命令:pip install requests

项目导入:import requests

三、各种请求方式

直接上代码,不明白可以查看我的urllib的基本使用方法

1 import requests2 requests.post(‘http://httpbin.org/post‘)3 requests.put(‘http://httpbin.org/put‘)4 requests.delete(‘http://httpbin.org/delete‘)5 requests.head(‘http://httpbin.org/get‘)6 requests.options(‘http://httpbin.org/get‘)

这么多请求方式,都有什么含义,所以问下度娘:


GET: 请求指定的页面信息,并返回实体主体。
HEAD: 只请求页面的首部。
POST: 请求服务器接受所指定的文档作为对所标识的URI的新的从属实体。
PUT: 从客户端向服务器传送的数据取代指定的文档的内容。
DELETE: 请求服务器删除指定的页面。
get 和 post比较常见 GET请求将提交的数据放置在HTTP请求协议头中
POST提交的数据则放在实体数据中
(1)、基本的GET请求

 1 import requests 2  3 response = requests.get(‘http://httpbin.org/get‘) 4 print(response.text) 5 返回值: 6  7 { 8   "args": {},  9   "headers": {10     "Accept": "*/*", 11     "Accept-Encoding": "gzip, deflate", 12     "Connection": "close", 13     "Host": "httpbin.org", 14     "User-Agent": "python-requests/2.18.4"15   }, 16   "origin": "183.64.61.29", 17   "url": "http://httpbin.org/get"18 }19 (2)、带参数的GET请求20 21 将name和age传进去22 23 import requests24 response = requests.get("http://httpbin.org/get?name=germey&age=22")25 print(response.text)26 {27   "args": {28     "age": "22", 29     "name": "germey"30   }, 31   "headers": {32     "Accept": "*/*", 33     "Accept-Encoding": "gzip, deflate", 34     "Connection": "close", 35     "Host": "httpbin.org", 36     "User-Agent": "python-requests/2.18.4"37   }, 38   "origin": "183.64.61.29", 39   "url": "http://httpbin.org/get?name=germey&age=22"40 }41 或者使用params的方法:42 43 import requests44 45 data = {46  ‘name‘: ‘germey‘,47  ‘age‘: 2248 }49 response = requests.get("http://httpbin.org/get", params=data)50 print(response.text)51 返回值一样52 53 (3)、解析json54 55 将返回值已json的形式展示:56 57 import requests58 import json59 60 response = requests.get("http://httpbin.org/get")61 print(type(response.text))62 print(response.json())63 print(json.loads(response.text))64 print(type(response.json()))65 返回值:66 67 <class ‘str‘>68 {‘args‘: {}, ‘headers‘: {‘Accept‘: ‘*/*‘, ‘Accept-Encoding‘: ‘gzip, deflate‘, ‘Connection‘: ‘close‘, ‘Host‘: ‘httpbin.org‘, ‘User-Agent‘: ‘python-requests/2.18.4‘}, ‘origin‘: ‘183.64.61.29‘, ‘url‘: ‘http://httpbin.org/get‘}69 {‘args‘: {}, ‘headers‘: {‘Accept‘: ‘*/*‘, ‘Accept-Encoding‘: ‘gzip, deflate‘, ‘Connection‘: ‘close‘, ‘Host‘: ‘httpbin.org‘, ‘User-Agent‘: ‘python-requests/2.18.4‘}, ‘origin‘: ‘183.64.61.29‘, ‘url‘: ‘http://httpbin.org/get‘}70 <class ‘dict‘>71 (4)、获取二进制数据72 73 记住返回值.content就ok了74 75 import requests76 77 response = requests.get("https://github.com/favicon.ico")78 print(type(response.text), type(response.content))79 print(response.text)80 print(response.content)

返回值为二进制不必再进行展示,

(5)、添加headers

有些网站访问时必须带有浏览器等信息,如果不传入headers就会报错,如下

 1 import requests 2  3 response = requests.get("https://www.zhihu.com/explore") 4 print(response.text) 5 返回值: 6  7 <html><body><h1>500 Server Error</h1> 8 An internal server error occured. 9 </body></html>10 当传入headers时:11 12 import requests13 14 headers = {15  ‘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‘16 }17 response = requests.get("https://www.zhihu.com/explore", headers=headers)18 print(response.text)


成功返回网页源代码不做展示

(6)、基本POST请求

不明白见我博文urllib的使用方法

 1 import requests 2  3 data = {‘name‘: ‘germey‘, ‘age‘: ‘22‘} 4 response = requests.post("http://httpbin.org/post", data=data) 5 print(response.text) 6 返回: 7  8 { 9   "args": {}, 10   "data": "", 11   "files": {}, 12   "form": {13     "age": "22", 14     "name": "germey"15   }, 16   "headers": {17     "Accept": "*/*", 18     "Accept-Encoding": "gzip, deflate", 19     "Connection": "close", 20     "Content-Length": "18", 21     "Content-Type": "application/x-www-form-urlencoded", 22     "Host": "httpbin.org", 23     "User-Agent": "python-requests/2.18.4"24   }, 25   "json": null, 26   "origin": "183.64.61.29", 27   "url": "http://httpbin.org/post"28 }

三、响应

response属性

 1 import requests 2  3 response = requests.get(‘http://www.jianshu.com‘) 4 print(type(response.status_code), response.status_code) 5 print(type(response.headers), response.headers) 6 print(type(response.cookies), response.cookies) 7 print(type(response.url), response.url) 8 print(type(response.history), response.history) 9 return:10 11 <class ‘int‘> 20012 <class ‘requests.structures.CaseInsensitiveDict‘> {‘Date‘: ‘Thu, 01 Feb 2018 20:47:08 GMT‘, ‘Server‘: ‘Tengine‘, ‘Content-Type‘: ‘text/html; charset=utf-8‘, ‘Transfer-Encoding‘: ‘chunked‘, ‘X-Frame-Options‘: ‘DENY‘, ‘X-XSS-Protection‘: ‘1; mode=block‘, ‘X-Content-Type-Options‘: ‘nosniff‘, ‘ETag‘: ‘W/"9f70e869e7cce214b6e9d90f4ceaa53d"‘, ‘Cache-Control‘: ‘max-age=0, private, must-revalidate‘, ‘Set-Cookie‘: ‘locale=zh-CN; path=/‘, ‘X-Request-Id‘: ‘366f4cba-8414-4841-bfe2-792aeb8cf302‘, ‘X-Runtime‘: ‘0.008350‘, ‘Content-Encoding‘: ‘gzip‘, ‘X-Via‘: ‘1.1 gjf22:8 (Cdn Cache Server V2.0), 1.1 PSzqstdx2ps251:10 (Cdn Cache Server V2.0)‘, ‘Connection‘: ‘keep-alive‘}13 <class ‘requests.cookies.RequestsCookieJar‘> <RequestsCookieJar[<Cookie locale=zh-CN for www.jianshu.com/>]>14 <class ‘str‘> https://www.jianshu.com/15 <class ‘list‘> [<Response [301]>]16 状态码判断:常见的网页状态码:17 18 100: (‘continue‘,),19 101: (‘switching_protocols‘,),20 102: (‘processing‘,),21 103: (‘checkpoint‘,),22 122: (‘uri_too_long‘, ‘request_uri_too_long‘),23 200: (‘ok‘, ‘okay‘, ‘all_ok‘, ‘all_okay‘, ‘all_good‘, ‘\\o/‘, ‘?‘),24 201: (‘created‘,),25 202: (‘accepted‘,),26 203: (‘non_authoritative_info‘, ‘non_authoritative_information‘),27 204: (‘no_content‘,),28 205: (‘reset_content‘, ‘reset‘),29 206: (‘partial_content‘, ‘partial‘),30 207: (‘multi_status‘, ‘multiple_status‘, ‘multi_stati‘, ‘multiple_stati‘),31 208: (‘already_reported‘,),32 226: (‘im_used‘,),33 34 # Redirection.35 300: (‘multiple_choices‘,),36 301: (‘moved_permanently‘, ‘moved‘, ‘\\o-‘),37 302: (‘found‘,),38 303: (‘see_other‘, ‘other‘),39 304: (‘not_modified‘,),40 305: (‘use_proxy‘,),41 306: (‘switch_proxy‘,),42 307: (‘temporary_redirect‘, ‘temporary_moved‘, ‘temporary‘),43 308: (‘permanent_redirect‘,44  ‘resume_incomplete‘, ‘resume‘,), # These 2 to be removed in 3.045 46 # Client Error.47 400: (‘bad_request‘, ‘bad‘),48 401: (‘unauthorized‘,),49 402: (‘payment_required‘, ‘payment‘),50 403: (‘forbidden‘,),51 404: (‘not_found‘, ‘-o-‘),52 405: (‘method_not_allowed‘, ‘not_allowed‘),53 406: (‘not_acceptable‘,),54 407: (‘proxy_authentication_required‘, ‘proxy_auth‘, ‘proxy_authentication‘),55 408: (‘request_timeout‘, ‘timeout‘),56 409: (‘conflict‘,),57 410: (‘gone‘,),58 411: (‘length_required‘,),59 412: (‘precondition_failed‘, ‘precondition‘),60 413: (‘request_entity_too_large‘,),61 414: (‘request_uri_too_large‘,),62 415: (‘unsupported_media_type‘, ‘unsupported_media‘, ‘media_type‘),63 416: (‘requested_range_not_satisfiable‘, ‘requested_range‘, ‘range_not_satisfiable‘),64 417: (‘expectation_failed‘,),65 418: (‘im_a_teapot‘, ‘teapot‘, ‘i_am_a_teapot‘),66 421: (‘misdirected_request‘,),67 422: (‘unprocessable_entity‘, ‘unprocessable‘),68 423: (‘locked‘,),69 424: (‘failed_dependency‘, ‘dependency‘),70 425: (‘unordered_collection‘, ‘unordered‘),71 426: (‘upgrade_required‘, ‘upgrade‘),72 428: (‘precondition_required‘, ‘precondition‘),73 429: (‘too_many_requests‘, ‘too_many‘),74 431: (‘header_fields_too_large‘, ‘fields_too_large‘),75 444: (‘no_response‘, ‘none‘),76 449: (‘retry_with‘, ‘retry‘),77 450: (‘blocked_by_windows_parental_controls‘, ‘parental_controls‘),78 451: (‘unavailable_for_legal_reasons‘, ‘legal_reasons‘),79 499: (‘client_closed_request‘,),80 81 # Server Error.82 500: (‘internal_server_error‘, ‘server_error‘, ‘/o\\‘, ‘?‘),83 501: (‘not_implemented‘,),84 502: (‘bad_gateway‘,),85 503: (‘service_unavailable‘, ‘unavailable‘),86 504: (‘gateway_timeout‘,),87 505: (‘http_version_not_supported‘, ‘http_version‘),88 506: (‘variant_also_negotiates‘,),89 507: (‘insufficient_storage‘,),90 509: (‘bandwidth_limit_exceeded‘, ‘bandwidth‘),91 510: (‘not_extended‘,),92 511: (‘network_authentication_required‘, ‘network_auth‘, ‘network_authentication‘),

四、高级操作

(1)、文件上传

使用 Requests 模块,上传文件也是如此简单的,文件的类型会自动进行处理:

实例:

import requests

files = {‘file‘: open(‘cookie.txt‘, ‘rb‘)}
response = requests.post("http://httpbin.org/post", files=files)
print(response.text)
这是通过测试网站做的一个测试,返回值如下:

{
"args": {},
"data": "",
"files": {
"file": "#LWP-Cookies-2.0\r\nSet-Cookie3: BAIDUID=\"D2B4E137DE67E271D87F03A8A15DC459:FG=1\"; path=\"/\"; domain=\".baidu.com\"; path_spec; domain_dot; expires=\"2086-02-13 11:15:12Z\"; version=0\r\nSet-Cookie3: BIDUPSID=D2B4E137DE67E271D87F03A8A15DC459; path=\"/\"; domain=\".baidu.com\"; path_spec; domain_dot; expires=\"2086-02-13 11:15:12Z\"; version=0\r\nSet-Cookie3: H_PS_PSSID=25641_1465_21087_17001_22159; path=\"/\"; domain=\".baidu.com\"; path_spec; domain_dot; discard; version=0\r\nSet-Cookie3: PSTM=1516953672; path=\"/\"; domain=\".baidu.com\"; path_spec; domain_dot; expires=\"2086-02-13 11:15:12Z\"; version=0\r\nSet-Cookie3: BDSVRTM=0; path=\"/\"; domain=\"www.baidu.com\"; path_spec; discard; version=0\r\nSet-Cookie3: BD_HOME=0; path=\"/\"; domain=\"www.baidu.com\"; path_spec; discard; version=0\r\n"
},
"form": {},
"headers": {
"Accept": "*/*",
"Accept-Encoding": "gzip, deflate",
"Connection": "close",
"Content-Length": "909",
"Content-Type": "multipart/form-data; boundary=84835f570cfa44da8f4a062b097cad49",
"Host": "httpbin.org",
"User-Agent": "python-requests/2.18.4"
},
"json": null,
"origin": "183.64.61.29",
"url": "http://httpbin.org/post"
}

(2)、获取cookie

当需要cookie时,直接调用response.cookie技术分享图片response为请求后的返回值)

import requests

response = requests.get("https://www.baidu.com")
print(response.cookies)
for key, value in response.cookies.items():
print(key + ‘=‘ + value)

输出结果:

<RequestsCookieJar[<Cookie BDORZ=27315 for .baidu.com/>]>
BDORZ=27315
(3)、会话维持、模拟登陆

如果某个响应中包含一些Cookie,你可以快速访问它们:

import requests

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

要想发送你的cookies到服务器,可以使用 cookies 参数:

import requests

url = ‘http://httpbin.org/cookies‘
cookies = {‘testCookies_1‘: ‘Hello_Python3‘, ‘testCookies_2‘: ‘Hello_Requests‘}
# 在Cookie Version 0中规定空格、方括号、圆括号、等于号、逗号、双引号、斜杠、问号、@,冒号,分号等
特殊符号都不能作为Cookie的内容。
r = requests.get(url, cookies=cookies)
print(r.json())
(4)、证书验证

因为12306有一个错误证书,我们那它的网站做测试会出现下面的情况,证书不是官方证书,浏览器会识别出
一个错误

import requests

response = requests.get(‘https://www.12306.cn‘)
print(response.status_code)
返回值:





怎么正常进入这样的网站了,代码如下:

import requests
from requests.packages import urllib3
urllib3.disable_warnings()
response = requests.get(‘https://www.12306.cn‘, verify=False)
print(response.status_code)
将verify设置位False即可,返回的状态码为200


urllib3.disable_warnings()这条命令主要用于消除警告信息

(5)、代理设置

在进行爬虫爬取时,有时候爬虫会被服务器给屏蔽掉,这时采用的方法主要有降低访问时间,通过代理ip访问,
如下:

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)
ip可以从网上抓取,或者某宝购买

如果代理需要设置账户名和密码,只需要将字典更改为如下:
proxies = {
"http":"http://user:[email protected]:9999"
}
如果你的代理是通过sokces这种方式则需要pip install "requests[socks]"
proxies= {
"http":"socks5://127.0.0.1:9999",
"https":"sockes5://127.0.0.1:8888"
}

(6)、超时设置

访问有些网站时可能会超时,这时设置好timeout就可以解决这个问题

import requests
from requests.exceptions import ReadTimeout
try:
response = requests.get("http://httpbin.org/get", timeout = 0.5)
print(response.status_code)
except ReadTimeout:
print(‘Timeout‘)

正常访问,状态吗返回200

(7)、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

import requests

from requests.auth import HTTPBasicAuth

response = requests.get("http://120.27.34.24:9001/",auth=HTTPBasicAuth("user","123"))
print(response.status_code)
当然这里还有一种方式

import requests

response = requests.get("http://120.27.34.24:9001/",auth=("user","123"))
print(response.status_code)
(8)、异常处理

遇到网络问题(如:DNS查询失败、拒绝连接等)时,Requests会抛出一个ConnectionError 异常。

遇到罕见的无效HTTP响应时,Requests则会抛出一个 HTTPError 异常。

若请求超时,则抛出一个 Timeout 异常。

若请求超过了设定的最大重定向次数,则会抛出一个 TooManyRedirects 异常。

所有Requests显式抛出的异常都继承自 requests.exceptions.RequestException 。

python中requests库使用方法详解

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