python requests用法總結
requests是一個很實用的Python HTTP客戶端庫，編寫爬蟲和測試服務器響應數據時經常會用到。可以說，Requests 完全滿足如今網絡的需求
本文全部來源於官方文檔:
http://docs.python-requests.org/en/master/
http://cn.python-requests.org/zh_CN/latest/
安裝方式一般採用pip install requests。其它安裝方式參考官方文檔
導入模塊： import requests
一、GET請求
r = requests.get('http://httpbin.org/get')
傳參
>>> payload = {'key1': 'value1', 'key2': 'value2', 'key3': None}
>>> r = requests.get('http://httpbin.org/get', params=payload)
http://httpbin.org/get?key2=value2&key1=value1
Note that any dictionary key whose value is None will not be added to the URL's query string.
參數也可以傳遞列表
>>> payload = {'key1': 'value1', 'key2': ['value2', 'value3']}
>>> r = requests.get('http://httpbin.org/get', params=payload)
>>> print(r.url)
http://httpbin.org/get?key1=value1&key2=value2&key2=value3
r.text 返回headers中的編碼解析的結果，可以通過r.encoding = 'gbk'來變更解碼方式
r.content 返回二進制結果
r.json() 返回JSON格式，可能拋出異常
r.status_code
r.raw 返回原始socket respons，需要加參數stream=True
>>> r = requests.get('https://api.github.com/events', stream=True)
>>> r.raw
<requests.packages.urllib3.response.HTTPResponse object at 0x101194810>
>>> r.raw.read(10)
'\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\x03'
將結果保存到文件，利用r.iter_content()
with open(filename, 'wb') as fd:
for chunk in r.iter_content(chunk_size):
fd.write(chunk)
傳遞headers
>>> headers = {'user-agent': 'my-app/0.0.1'}
>>> r = requests.get(url, headers=headers)
傳遞cookies
>>> url = 'http://httpbin.org/cookies'
>>> r = requests.get(url, cookies=dict(cookies_are='working'))
>>> r.text
'{"cookies": {"cookies_are": "working"}}'
二、POST請求
傳遞表單
r = requests.post('http://httpbin.org/post', data = {'key':'value'})
通常，你想要發送一些編碼爲表單形式的數據—非常像一個HTML表單。 要實現這個，只需簡單地傳遞一個字典給 data 參數。你的數據字典在發出請求時會自動編碼爲表單形式:
>>> payload = {'key1': 'value1', 'key2': 'value2'}
>>> r = requests.post("http://httpbin.org/post", data=payload)
>>> print(r.text)
{
...
"form": {
"key2": "value2",
"key1": "value1"
},
...
}
很多時候你想要發送的數據並非編碼爲表單形式的。如果你傳遞一個 string 而不是一個dict ，那麼數據會被直接發佈出去。
>>> url = 'https://api.github.com/some/endpoint'
>>> payload = {'some': 'data'}
>>> r = requests.post(url, data=json.dumps(payload))
或者
>>> r = requests.post(url, json=payload)
傳遞文件
url = 'http://httpbin.org/post'
>>> files = {'file': open('report.xls', 'rb')}
>>> r = requests.post(url, files=files)
配置files，filename, content_type and headers
files = {'file': ('report.xls', open('report.xls', 'rb'), 'application/vnd.ms-excel', {'Expires': '0'})}
files = {'file': ('report.csv', 'some,data,to,send\nanother,row,to,send\n')}
響應
r.status_code
r.heards
r.cookies
跳轉
By default Requests will perform location redirection for all verbs except HEAD.
>>> r = requests.get('http://httpbin.org/cookies/set?k2=v2&k1=v1')
>>> r.url
'http://httpbin.org/cookies'
>>> r.status_code
200
>>> r.history
[<Response [302]>]
If you're using HEAD, you can enable redirection as well:
r = requests.head('http://httpbin.org/cookies/set?k2=v2&k1=v1',allow_redirects=True)
You can tell Requests to stop waiting for a response after a given number of seconds with the timeoutparameter:
requests.get('http://github.com', timeout=0.001)
參考文章：http://www.cnblogs.com/lilinwei340/p/6417689.html