python爬虫04 | 长江后浪推前浪，Requests库把urllib库拍在沙滩上

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盘他

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接下来我们要来玩一个新的库

这个库的名称叫做

Requests

这个库比我们上次说的 urllib 可是要牛逼一丢丢的

毕竟 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

人生苦短

接下来就是

学习 python 的正确姿势

skr

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

安装完后就可以使用了

接下来就来感受一下 requests 吧

导入 requests 模块

import requests

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')

想要携带请求参数是吧？

>>> 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/...

>>> 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_code

200

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)

'x1fx8bx08x00x00x00x00x00x00x03'

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.text

True

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)