爬虫笔记：Requests库详解

朴灿烈づ我的快乐病毒、 2023-01-10 14:45 160阅读 0赞

## 什么是Requests ##

之前讲解了[爬虫笔记：Urllib库详解][Urllib]发现确实有不方便的地方，比如加一个代理，cookie，发送post请求比较繁琐。  
Request库能用几句话实现这些。

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  
安装

> > pip3 install requests  
> > 或者  
> > pip install requests

## 用法讲解 ##

**实例引入**

import requests
    
    response = requests.get(r'https://www.2345.com/?38001')
    print(type(response))
    print(response.status_code)#状态码
    print(type(response.text))
    print(response.text)#文本
    print(response.cookies)#cookies
    print('结束')

![20210125094516570.png_pic_center][] ![20210125094536103.png_pic_center][]

**各种请求方式**

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')

基本get请求

import requests
    
    response = requests.get('http://httpbin.org/get')
    print(response.text)

![20210125094930709.png_pic_center][]

带参数的get请求  
（在url后拼接，需要用？号分割，用&与号进行连接）

### 带参数GET请求
    import requests
    response = requests.get("http://httpbin.org/get?name=germey&age=22")
    print(response.text)

> > 参数在args中  
> > ![20210125095205618.png_pic_center][]

带参数的get请求（前面用？& 比较复杂，可以用字典形式进行传值）

import requests
    
    data = { 
        'name': 'germey',
        'age': 22
    }
    response = requests.get("http://httpbin.org/get", params=data)
    print(response.text)

![20210125095439613.png_pic_center][]

**解析json**

import requests
    import json
    
    response = requests.get("http://httpbin.org/get")
    print(type(response.text))
    print(response.json())#response直接解析成json
    print(json.loads(response.text))#通过json解析库来解析
    print(type(response.json()))

![20210125095656207.png_pic_center][]

**获取二进制数据**  
二进制数据指图片或者视频

import requests
    
    response = requests.get("https://github.com/favicon.ico")
    print(type(response.text), type(response.content))
    print(response.text)
    print(response.content)

![2021012510203272.png_pic_center][]

图片下载

import requests
    
    response = requests.get("https://github.com/favicon.ico")
    with open('favicon.ico', 'wb') as f:
        f.write(response.content)
        f.close()

**添加headers**  
在进行爬虫时添加headers很有必要，如果不添加，很可能把你禁掉

import requests
    
    headers = { 'User-Agent':
               'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3947.100 Safari/537.36'}
    response = requests.get("https://blog.csdn.net/KOBEYU652453/", headers=headers)
    print(response.text)

![20210125102735177.png_pic_center][]

**基本POST请求**

import requests
    
    data = { 'name': 'germey', 'age': '22'}
    response = requests.post("http://httpbin.org/post", data=data)
    print(response.text)

带headers

import requests
    
    data = { 'name': 'germey', 'age': '22'}
    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.post("http://httpbin.org/post", data=data, headers=headers)
    print(response.json())

![20210125103010272.png_pic_center][]

**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)#请求头
    print(type(response.cookies), response.cookies)#cookies
    print(type(response.url), response.url)#网址
    print(type(response.history), response.history)#访问历史记录

![20210125103543246.png_pic_center][]

**状态码判断**

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'),

import requests
    
    response = requests.get('http://www.jianshu.com')
    exit() if not response.status_code == 200 else print('Request Successfully')

**高级操作**

文件上传

import requests
    
    files = { 'file': open('meinv.jpg', 'rb')}#打开本地文件
    response = requests.post("http://httpbin.org/post", files=files)
    print(response.text)

![2021012519022049.png_pic_center][]

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)

![20210125191012981.png_pic_center][]

模拟登录

先设置cookies，再获取cookies

import requests
    
    requests.get('http://httpbin.org/cookies/set/number/123456789')#先设置cookies ：number/123456789
    response = requests.get('http://httpbin.org/cookies')#拿到cookies
    print(response.text)

cookie 为空，因为代码中的l两次get为独立请求。等于说一个浏览器里设置了cookie,再用另一个浏览器访问。  
![20210125191503218.png_pic_center][]

如果要维持，必须先声明session 对象。

import requests
    
    s = requests.Session()#打开一个会话
    s.get('http://httpbin.org/cookies/set/number/123456789')
    response = s.get('http://httpbin.org/cookies')
    print(response.text)

![20210125192057393.png_pic_center][]

代理设置

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)

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)

超时设置

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')

![20210125194147224.png_pic_center][]

异常处理

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:#超时
        print('Timeout')
    except ConnectionError:#网络问题
        print('Connection error')
    except RequestException:#其他问题
        print('Error')

认证设置

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

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

![在这里插入图片描述][20210125194827700.jpg_pic_center]  
作者：电气-余登武

[Urllib]: https://blog.csdn.net/KOBEYU652453/article/details/112977309
[20210125094516570.png_pic_center]: https://img-blog.csdnimg.cn/20210125094516570.png#pic_center
[20210125094536103.png_pic_center]: /images/20221119/ba92219bc78a4d8796b4b068662a2b38.png
[20210125094930709.png_pic_center]: /images/20221119/8dccbb16c02c4f5c88affe923e2bc848.png
[20210125095205618.png_pic_center]: /images/20221119/461703bb403844cc843baf3f9e6d3987.png
[20210125095439613.png_pic_center]: https://img-blog.csdnimg.cn/20210125095439613.png#pic_center
[20210125095656207.png_pic_center]: https://img-blog.csdnimg.cn/20210125095656207.png#pic_center
[2021012510203272.png_pic_center]: https://img-blog.csdnimg.cn/2021012510203272.png#pic_center
[20210125102735177.png_pic_center]: https://img-blog.csdnimg.cn/20210125102735177.png#pic_center
[20210125103010272.png_pic_center]: https://img-blog.csdnimg.cn/20210125103010272.png#pic_center
[20210125103543246.png_pic_center]: https://img-blog.csdnimg.cn/20210125103543246.png#pic_center
[2021012519022049.png_pic_center]: https://img-blog.csdnimg.cn/2021012519022049.png#pic_center
[20210125191012981.png_pic_center]: https://img-blog.csdnimg.cn/20210125191012981.png#pic_center
[20210125191503218.png_pic_center]: https://img-blog.csdnimg.cn/20210125191503218.png#pic_center
[20210125192057393.png_pic_center]: https://img-blog.csdnimg.cn/20210125192057393.png#pic_center
[20210125194147224.png_pic_center]: https://img-blog.csdnimg.cn/20210125194147224.png#pic_center
[20210125194827700.jpg_pic_center]: https://img-blog.csdnimg.cn/20210125194827700.jpg#pic_center