Python urllib3软件包的使用说明

urllib3是一款Python 3的HTTP客户端。

Python标准库提供了urllib。在Python 2中，另外提供了urllib2；而在Python 3中，重构了urllib和urllib2到标准库urllib，并另外提供了urllib3。

1. urllib3的特性

线程安全

连接缓冲池

客户端SSL/TLS验证

文件上传

请求重试

HTTP重定向

支持gzip和deflate encoding

支持HTTP和SOCKS的代理

2. 安装

urllib3不是Python 3的标准库，要使用需要另外安装，pip命令如下：

pip install urllib3

3. 用法

1) HTTP GET请求

>>> import urllib3
>>> http = urllib3.PoolManager()
>>> r = http.request('GET', 'http://httpbin.org/robots.txt')
>>> r.status
200
>>> r.data
...
>>> r.headers
...

注意：任何HTTP请求，只有通过PoolManager对象发出，才能够提供连接缓冲池和线程安全特性。

任何请求的返回对象都是HTTPResponse对象，其中包含status, data和headers三个属性。

2) HTTP POST请求

>>> import urllib3
>>> http = urllib3.PoolManager()
>>> r = http.request('POST', 'http://httpbin.org/post', fields={'hello': 'Xiangbin'})
>>> r.status
200
>>> r.data
...
>>> r.headers
...

3) JSON响应的处理

>>> import urllib3
>>> import json
 
>>> http = urllib3.PoolManager()
>>> r = http.request('GET', 'http://httpbin.org/ip')
>>> r.data
b'{\n "origin": "10.23.1.37"\n}\n'
>>> json.loads(r.data.decode('utf-8'))
{'origin': '127.0.0.1'}

注意：使用json的loads()方法

4) 流式响应的处理

>>> import urllib3
>>> http = urllib3.PoolManager()
>>> r = http.request('GET', 'http://httpbin.org/bytes/1024', preload_content=False)
>>> for chunk in r.stream(32):
...   print(chunk)
...
>>> r.release_conn()

注意：preload_content=False表示流式处理响应数据。

处理stream()方法读取响应数据之外，还可以使用read()方法，示例如下：

>>> import urllib3
>>> http = urllib3.PoolManager()
>>> r = http.request('GET', 'http://httpbin.org/bytes/1024', preload_content=False)
>>> r.read(4)
b'\x88\x1f\x8b\xe5' 
>>> r.release_conn()

5) 请求带参数

>>> r = http.request('GET', 'http://httpbin.org/headers', fields={'hello': 'Xiangbin'}, headers={'X-Something': 'value'})

对于POST和PUT方法，需要将参数编码后，这样才可以追加到URL，示例如下：

>>> from urllib.parse import urlencode
>>> encoded_args = urlencode({'arg': 'value'})
>>> url = 'http://httpbin.org/post?' + encoded_args
>>> r = http.request('POST', url)

当然，最好还是以fields参数形式，urllib3将自动编码，示例如下：

>>> r = http.request('POST', 'http://httpbin.org/post', fields={'hello': 'Xiangbin'})

使用JSON模块，还可以以body形式发送请求参数，示例如下：

>>> import json
>>> data = {'Hello': 'Xiangbin'}
>>> encoded_data = json.dumps(data).encode('utf-8')
>>> r = http.request('POST', 'http://httpbin.org/post', body=encoded_data, headers={'Content-Type': 'application/json'})
>>> json.loads(r.data.decode('utf-8'))['json']
{'Hello': 'Xiangbin'}

6) 上传文件

文本文件

>>> with open('example.txt') as fp:
...   file_data = fp.read()
>>> r = http.request(
...   'POST',
...   'http://httpbin.org/post',
...   fields={
...     'filefield': ('example.txt', file_data, 'text/plain'),
...   })
>>> json.loads(r.data.decode('utf-8'))['files']
{'filefield': '...'}

注意：上传文件必须使用POST方法。

二进制文件

>>> with open('example.jpg', 'rb') as fp:
...   binary_data = fp.read()
>>> r = http.request(
...   'POST',
...   'http://httpbin.org/post',
...   body=binary_data,
...   headers={'Content-Type': 'image/jpeg'})
>>> json.loads(r.data.decode('utf-8'))['data']
b'...'

补充知识：Python的requests软件包详解

requests是一款Python的第三方HTTP类库，便于进行HTTP访问。

1. requests的特性

能够发送HTTP 1.1请求

无需手工为GET方法设置URL的请求参数，无需手工为POST方法组编码表单形式

借助于urllib3实现HTTP请求的连接会话缓存

支持Python 2.6, 2.7, 3.3-3.7

2. requests的安装

requests不是Python标准库，需要使用PIP安装，命令如下：

pip install requests

安装过程如下：

C:\Sam\works>pip install requests
Collecting requests
 Downloading https://files.pythonhosted.org/packages/51/bd/23c926cd341ea6b7dd0b2a00aba99ae0f828be89d72b2190f27c11d4b7fb/requests-2.22.0-py2.py3-none-any.whl (57kB)
  100% |????????????????????????????????| 61kB 17kB/s
Collecting certifi>=2017.4.17 (from requests)
 Downloading https://files.pythonhosted.org/packages/18/b0/8146a4f8dd402f60744fa380bc73ca47303cccf8b9190fd16a827281eac2/certifi-2019.9.11-py2.py3-none-any.whl (154kB)
  100% |????????????????????????????????| 163kB 18kB/s
Collecting idna<2.9,>=2.5 (from requests)
 Downloading https://files.pythonhosted.org/packages/14/2c/cd551d81dbe15200be1cf41cd03869a46fe7226e7450af7a6545bfc474c9/idna-2.8-py2.py3-none-any.whl (58kB)
  100% |????????????????????????????????| 61kB 10kB/s
Collecting urllib3!=1.25.0,!=1.25.1,<1.26,>=1.21.1 (from requests)
 Downloading https://files.pythonhosted.org/packages/e0/da/55f51ea951e1b7c63a579c09dd7db825bb730ec1fe9c0180fc77bfb31448/urllib3-1.25.6-py2.py3-none-any.whl (125kB)
  100% |????????????????????????????????| 133kB 32kB/s
Collecting chardet<3.1.0,>=3.0.2 (from requests)
 Downloading https://files.pythonhosted.org/packages/bc/a9/01ffebfb562e4274b6487b4bb1ddec7ca55ec7510b22e4c51f14098443b8/chardet-3.0.4-py2.py3-none-any.whl (133kB)
  100% |????????????????????????????????| 143kB 48kB/s
Installing collected packages: certifi, idna, urllib3, chardet, requests
Successfully installed certifi-2019.9.11 chardet-3.0.4 idna-2.8 requests-2.22.0 urllib3-1.25.6
You are using pip version 19.0.3, however version 19.3.1 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.

3. requests的接口

1) Main interfaces

requests.request()
requests.head()
requests.get('url', params={'key1':'value1', 'key2':'value2'},headers={'user-agent': '...'}, cookies={'name1':'value2'})
requests.post('url', data={'key':'value'})
requests.post('url', json={'key':'value'})
requests.post('url', files={'uploaded_file': open('report.xls', 'rb')})
requests.post('url', files={'uploaded_file': ('report.xls', open('report.xls', 'rb'), 'application/excel', {'Expires': '0'})})
requests.post('url', files={'uploaded_file': ('temp.txt', 'one line\ntwo lines\n')})
requests.put('url', data={'key':'value'})
requests.patch()
requests.delete('url')
def getGithub():
  github_url = 'https://api.github.com/user/repos'
  myresponse = requests.get(github_url, auth=('champagne', 'myPassword'))
  print(myresponse.json())
def postGithub():
  github_url = 'https://api.github.com/user/repos'
  data = json.dumps({'name':'python test', 'description':'a python test repo'})
  myresponse = requests.post(github_url, data, auth=('champagne', 'myPassword'))
  print(myresponse.text)

2) requests.Session类

import requests

requests.Session()

3) requests.Request类

import requests

requests.Request('GET', 'http://httpbin.org/get')

4) requests.PreparedRequest类

import requests
req = requests.Request('GET', 'http://httpbin.org/get')
preq = req.prepare()

5) requests.Response类

import requests
r = requests.get('https://api.github.com/events')
r.headers['content-type'] #'application/json;charset=utf8'
r.url
r.status_code #200==requests.codes.ok
r.encoding #'utf-8' by default
r.raw #raw content
r.text #text content
r.content #binary content
r.json()#json content, recommended
r.cookies['a_key']

注意：调用json()方法，如果返回结果不是有效的JSON数据，则抛出ValueError异常。

6) requests.adapters.BaseAdapter类

7) requests.adapters.HTTPAdapter类

requests提供的使用urllib3的HTTP Adapter

以上这篇Python urllib3软件包的使用说明就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持三水点靠木。