python3爬虫-2.requests库

requests

requests 是在 urllib 的基础上搞出来的,通过它我们可以用更少的代码,模拟浏览器操作,使用比urllib方便

对于不是 python 的内置库

我们需要安装一下,直接使用 pip 安装pip install requests

导入 requests 模块

import requests

具体使用

一行代码 Get 请求

r = requests.get('https://api.github.com/events')

一行代码 Post 请求

r = requests.post('https://httpbin.org/post', data = {'key':'value'})

其它乱七八糟的 Http 请求

>>> r = requests.put('https://httpbin.org/put', data = {'key':'value'})

>>> r = requests.delete('https://httpbin.org/delete')

>>> r = requests.head('https://httpbin.org/get')

>>> r = requests.options('https://httpbin.org/get')

想要携带请求参数？

>>> payload = {'key1': 'value1', 'key2': 'value2'}

>>> r = requests.get('https://httpbin.org/get', params=payload)

假装自己是浏览器

>>> url = 'https://api.github.com/some/endpoint'

>>> headers = {'user-agent': 'my-app/0.0.1'}

>>> r = requests.get(url, headers=headers)

获取服务器响应文本内容

>>> import requests

>>> r = requests.get('https://api.github.com/events')

>>> r.text

u'[{"repository":{"open_issues":0,"url":"https://github.com/...">https://github.com/...

>>> r.encoding

'utf-8'

获取字节响应内容

>>> r.content

b'[{"repository":{"open_issues":0,"url":"https://github.com/...

获取响应码

>>> r = requests.get('https://httpbin.org/get')>>> r.status_code200

获取响应头

>>> r.headers{        
        'content-encoding': 'gzip',        
        'transfer-encoding': 'chunked',      
        'connection': 'close',        
        'server': 'nginx/1.0.4',        
        'x-runtime': '148ms',        
        'etag': '"e1ca502697e5c9317743dc078f67693f"',       
        'content-type': 'application/json'    
        }

获取 Json 响应内容

>>> import requests
>>> r = requests.get('https://api.github.com/events')
>>> r.json()
[{u'repository': {u'open_issues': 0, u'url': 'https://github.com/...

获取 socket 流响应内容

>>> r = requests.get('https://api.github.com/events', stream=True)
>>> r.raw
<urllib3.response.HTTPResponse object at 0x101194810
>>>> r.raw.read(10)
'\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\x03'

Post请求

当你想要一个键里面添加多个值的时候

>>> payload_tuples = [('key1', 'value1'), ('key1', 'value2')]

>>> r1 = requests.post('https://httpbin.org/post', data=payload_tuples)

>>> payload_dict = {'key1': ['value1', 'value2']}

>>> r2 = requests.post('https://httpbin.org/post', data=payload_dict)

>>> print(r1.text)

{  ...  "form": {    "key1": [      "value1",      "value2"    ]  },  ...}

>>> r1.text == r2.textTrue

请求的时候用 json 作为参数

>>> url = 'https://api.github.com/some/endpoint'

>>> payload = {'some': 'data'}

>>> r = requests.post(url, json=payload)

想上传文件？

>>> url = 'https://httpbin.org/post'

>>> files = {'file': open('report.xls', 'rb')}

>>> r = requests.post(url, files=files)

>>> r.text

{  ...  "files": {    "file": "<censored...binary...data>"  },  ...}

获取 cookie 信息

>>> url = 'http://example.com/some/cookie/setting/url'

>>> r = requests.get(url)

>>> r.cookies['example_cookie_name']

'example_cookie_value'

发送 cookie 信息

>>> url = 'https://httpbin.org/cookies'

>>> cookies = dict(cookies_are='working')

>>> r = requests.get(url, cookies=cookies)

>>> r.text

'{"cookies": {"cookies_are": "working"}}'

设置超时

>>> requests.get('https://github.com/', timeout=0.001)

Traceback (most recent call last):  

File "<stdin>", line 1, in <module>requests.exceptions.Timeout: 

        HTTPConnectionPool(host='github.com', port=80): 

                Request timed out. (timeout=0.001)

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