python的import requests代表什么意思

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一、什么是Requests

Requests 是⽤Python语⾔编写,基于urllib,采⽤Apache2 Licensed开源协议的 HTTP 库。它⽐ urllib 更加⽅便,可以节约我们⼤量的⼯作,完全满⾜HTTP测试需求。

⼀句话——Python实现的简单易⽤的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 requests
  2. 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:

  1. GET: 请求指定的页面信息,并返回实体主体。
  2. HEAD: 只请求页面的首部。
  3. 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。
  4. PUT: 从客户端向服务器传送的数据取代指定的文档的内容。
  5. DELETE: 请求服务器删除指定的页面。
  6. 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
  7. 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. response = requests.get(‘http://httpbin.org/get’)
  3. print(response.text)

 

返回值:

  1. {
  2. “args”: {},
  3. “headers”: {
  4. “Accept”: “*/*”,
  5. “Accept-Encoding”: “gzip, deflate”,
  6. “Connection”: “close”,
  7. “Host”: “httpbin.org”,
  8. “User-Agent”: “python-requests/2.18.4”
  9. },
  10. “origin”: “183.64.61.29”,
  11. “url”: “http://httpbin.org/get”
  12. }

 

(2)、带参数的GET请求

将name和age传进去

  1. import requests
  2. response = requests.get(“http://httpbin.org/get?name=germey&age=22”)
  3. print(response.text)

 

  1. {
  2. “args”: {
  3. “age”: “22”,
  4. “name”: “germey”
  5. },
  6. “headers”: {
  7. “Accept”: “*/*”,
  8. “Accept-Encoding”: “gzip, deflate”,
  9. “Connection”: “close”,
  10. “Host”: “httpbin.org”,
  11. “User-Agent”: “python-requests/2.18.4”
  12. },
  13. “origin”: “183.64.61.29”,
  14. “url”: “http://httpbin.org/get?name=germey&age=22”
  15. }

 

或者使用params的方法:

  1. import requests
  2. data = {
  3. ‘name’: ‘germey’,
  4. ‘age’: 22
  5. }
  6. response = requests.get(“http://httpbin.org/get”, params=data)
  7. print(response.text)

 

返回值一样

(3)、解析json

将返回值已json的形式展示:

  1. import requests
  2. import json
  3. response = requests.get(“http://httpbin.org/get”)
  4. print(type(response.text))
  5. print(response.json())
  6. print(json.loads(response.text))
  7. print(type(response.json()))

 

返回值:

  1. <classstr‘>
  2. {‘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’}
  3. {‘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’}
  4. <classdict‘>

 

(4)、获取二进制数据

记住返回值.content就ok了

  1. import requests
  2. response = requests.get(“https://github.com/favicon.ico”)
  3. print(type(response.text), type(response.content))
  4. print(response.text)
  5. 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. response = requests.get(“https://www.zhihu.com/explore”)
  3. print(response.text)

 

返回值:

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

 

当传入headers时:

  1. import requests
  2. headers = {
  3. ‘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’
  4. }
  5. response = requests.get(“https://www.zhihu.com/explore”, headers=headers)
  6. 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. data = {‘name’: ‘germey’, ‘age’: ’22’}
  3. response = requests.post(“http://httpbin.org/post”, data=data)
  4. print(response.text)

 

返回:

  1. {
  2. “args”: {},
  3. “data”: “”,
  4. “files”: {},
  5. “form”: {
  6. “age”: “22”,
  7. “name”: “germey”
  8. },
  9. “headers”: {
  10. “Accept”: “*/*”,
  11. “Accept-Encoding”: “gzip, deflate”,
  12. “Connection”: “close”,
  13. “Content-Length”: “18”,
  14. “Content-Type”: “application/x-www-form-urlencoded”,
  15. “Host”: “httpbin.org”,
  16. “User-Agent”: “python-requests/2.18.4”
  17. },
  18. “json”: null,
  19. “origin”: “183.64.61.29”,
  20. “url”: “http://httpbin.org/post”
  21. }

 

三、响应

response属性

  1. import requests
  2. response = requests.get(‘http://www.jianshu.com’)
  3. print(type(response.status_code), response.status_code)
  4. print(type(response.headers), response.headers)
  5. print(type(response.cookies), response.cookies)
  6. print(type(response.url), response.url)
  7. print(type(response.history), response.history)

 

return:

  1. <classint‘> 200
  2. <classrequests.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’}
  3. <classrequests.cookies.RequestsCookieJar‘> <RequestsCookieJar[<Cookie locale=zh-CN for www.jianshu.com/>]>
  4. <classstr‘> https://www.jianshu.com/
  5. <classlist‘> [<Response [301]>]

 

状态码判断:常见的网页状态码:

  1. 100: (‘continue’,),
  2. 101: (‘switching_protocols’,),
  3. 102: (‘processing’,),
  4. 103: (‘checkpoint’,),
  5. 122: (‘uri_too_long’, ‘request_uri_too_long’),
  6. 200: (‘ok’, ‘okay’, ‘all_ok’, ‘all_okay’, ‘all_good’, ‘\\o/’, ‘✓’),
  7. 201: (‘created’,),
  8. 202: (‘accepted’,),
  9. 203: (‘non_authoritative_info’, ‘non_authoritative_information’),
  10. 204: (‘no_content’,),
  11. 205: (‘reset_content’, ‘reset’),
  12. 206: (‘partial_content’, ‘partial’),
  13. 207: (‘multi_status’, ‘multiple_status’, ‘multi_stati’, ‘multiple_stati’),
  14. 208: (‘already_reported’,),
  15. 226: (‘im_used’,),
  16. # Redirection.
  17. 300: (‘multiple_choices’,),
  18. 301: (‘moved_permanently’, ‘moved’, ‘\\o-‘),
  19. 302: (‘found’,),
  20. 303: (‘see_other’, ‘other’),
  21. 304: (‘not_modified’,),
  22. 305: (‘use_proxy’,),
  23. 306: (‘switch_proxy’,),
  24. 307: (‘temporary_redirect’, ‘temporary_moved’, ‘temporary’),
  25. 308: (‘permanent_redirect’,
  26. ‘resume_incomplete’, ‘resume’,), # These 2 to be removed in 3.0
  27. # Client Error.
  28. 400: (‘bad_request’, ‘bad’),
  29. 401: (‘unauthorized’,),
  30. 402: (‘payment_required’, ‘payment’),
  31. 403: (‘forbidden’,),
  32. 404: (‘not_found’, ‘-o-‘),
  33. 405: (‘method_not_allowed’, ‘not_allowed’),
  34. 406: (‘not_acceptable’,),
  35. 407: (‘proxy_authentication_required’, ‘proxy_auth’, ‘proxy_authentication’),
  36. 408: (‘request_timeout’, ‘timeout’),
  37. 409: (‘conflict’,),
  38. 410: (‘gone’,),
  39. 411: (‘length_required’,),
  40. 412: (‘precondition_failed’, ‘precondition’),
  41. 413: (‘request_entity_too_large’,),
  42. 414: (‘request_uri_too_large’,),
  43. 415: (‘unsupported_media_type’, ‘unsupported_media’, ‘media_type’),
  44. 416: (‘requested_range_not_satisfiable’, ‘requested_range’, ‘range_not_satisfiable’),
  45. 417: (‘expectation_failed’,),
  46. 418: (‘im_a_teapot’, ‘teapot’, ‘i_am_a_teapot’),
  47. 421: (‘misdirected_request’,),
  48. 422: (‘unprocessable_entity’, ‘unprocessable’),
  49. 423: (‘locked’,),
  50. 424: (‘failed_dependency’, ‘dependency’),
  51. 425: (‘unordered_collection’, ‘unordered’),
  52. 426: (‘upgrade_required’, ‘upgrade’),
  53. 428: (‘precondition_required’, ‘precondition’),
  54. 429: (‘too_many_requests’, ‘too_many’),
  55. 431: (‘header_fields_too_large’, ‘fields_too_large’),
  56. 444: (‘no_response’, ‘none’),
  57. 449: (‘retry_with’, ‘retry’),
  58. 450: (‘blocked_by_windows_parental_controls’, ‘parental_controls’),
  59. 451: (‘unavailable_for_legal_reasons’, ‘legal_reasons’),
  60. 499: (‘client_closed_request’,),
  61. # Server Error.
  62. 500: (‘internal_server_error’, ‘server_error’, ‘/o\\’, ‘✗’),
  63. 501: (‘not_implemented’,),
  64. 502: (‘bad_gateway’,),
  65. 503: (‘service_unavailable’, ‘unavailable’),
  66. 504: (‘gateway_timeout’,),
  67. 505: (‘http_version_not_supported’, ‘http_version’),
  68. 506: (‘variant_also_negotiates’,),
  69. 507: (‘insufficient_storage’,),
  70. 509: (‘bandwidth_limit_exceeded’, ‘bandwidth’),
  71. 510: (‘not_extended’,),
  72. 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:

  1. import requests
  2. files = {‘file’: open(‘cookie.txt’, ‘rb’)}
  3. response = requests.post(“http://httpbin.org/post”, files=files)
  4. print(response.text)

 

这是通过测试网站做的一个测试,返回值如下:

  1. {
  2. “args”: {},
  3. “data”: “”,
  4. “files”: {
  5. “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”
  6. },
  7. “form”: {},
  8. “headers”: {
  9. “Accept”: “*/*”,
  10. “Accept-Encoding”: “gzip, deflate”,
  11. “Connection”: “close”,
  12. “Content-Length”: “909”,
  13. “Content-Type”: “multipart/form-data; boundary=84835f570cfa44da8f4a062b097cad49”,
  14. “Host”: “httpbin.org”,
  15. “User-Agent”: “python-requests/2.18.4”
  16. },
  17. “json”: null,
  18. “origin”: “183.64.61.29”,
  19. “url”: “http://httpbin.org/post”
  20. }

 

(2)、获取cookie

当需要cookie时,直接调用response.cookie:(response为请求后的返回值)

  1. import requests
  2. response = requests.get(“https://www.baidu.com”)
  3. print(response.cookies)
  4. for key, value in response.cookies.items():
  5. print(key + ‘=’ + value)

 

输出结果:

  1. <RequestsCookieJar[<Cookie BDORZ=27315 for .baidu.com/>]>
  2. 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:

  1. import requests
  2. r = requests.get(‘http://www.google.com.hk/’)
  3. print(r.cookies[‘NID’])
  4. print(tuple(r.cookies))

 

要想发送你的cookies到服务器,可以使用 cookies 参数:

  1. import requests
  2. url = ‘http://httpbin.org/cookies’
  3. cookies = {‘testCookies_1’: ‘Hello_Python3’, ‘testCookies_2’: ‘Hello_Requests’}
  4. # 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。
  5. r = requests.get(url, cookies=cookies)
  6. 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

  1. import requests
  2. response = requests.get(‘https://www.12306.cn’)
  3. print(response.status_code)

 

返回值:

怎么正常进入这样的网站了,代码如下:

  1. import requests
  2. from requests.packages import urllib3
  3. urllib3.disable_warnings()
  4. response = requests.get(‘https://www.12306.cn’, verify=False)
  5. 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:

  1. import requests
  2. proxies = {
  3. “http”: “http://127.0.0.1:9743”,
  4. “https”: “https://127.0.0.1:9743”,
  5. }
  6. response = requests.get(“https://www.taobao.com”, proxies=proxies)
  7. print(response.status_code)

 

ip可以从网上抓取,或者某宝购买

  1. 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:
  2. proxies = {
  3. “http”:”http://user:password@127.0.0.1:9999″
  4. }
  5. 如果你的代理是通过sokces这种方式则需要pip install “requests[socks]”
  6. proxies= {
  7. “http”:”socks5://127.0.0.1:9999″,
  8. “https”:”sockes5://127.0.0.1:8888″
  9. }

 

(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

  1. import requests
  2. from requests.exceptions import ReadTimeout
  3. try:
  4. response = requests.get(“http://httpbin.org/get”, timeout = 0.5)
  5. print(response.status_code)
  6. except ReadTimeout:
  7. 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

  1. import requests
  2. from requests.auth import HTTPBasicAuth
  3. response = requests.get(“http://120.27.34.24:9001/”,auth=HTTPBasicAuth(“user”,”123″))
  4. print(response.status_code)

 

当然这里还有一种方式

  1. import requests
  2. response = requests.get(“http://120.27.34.24:9001/”,auth=(“user”,”123″))
  3. 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 。

weiker原创,转载请附上链接:http://mathlabs.cn

 

 

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