python 以客户端形式通HTTP服务交互

11.1 我们需要以客户端的形式通过HTTP歇息访问多种服务。

• 使用urllib.request模块通常就可以满足要求。

from urllib import request,parse
url = 'http://httpbin.org/get'
parms = {
    'name1':'value1',
    'name2':'value2'
}
qs = parse.urlencode(parms)
u = request.urlopen(url+"?"+qs)
resp = u.read()
print(resp)

• 返回值为

~/ning-dashboard/tmp > python3 ttt.py
b'{\n  "args": {\n    "name1": "value1", \n    "name2": "value2"\n  }, \n  "headers": {\n    "Accept-Encoding": "identity", \n    "Host": "httpbin.org", \n    "User-Agent": "Python-urllib/3.7", \n    "X-Amzn-Trace-Id": "Root=1-6298de82-639ab39566b89bc35bd45c7a"\n  }, \n  "origin": "210.22.74.111", \n  "url": "http://httpbin.org/get?name1=value1&name2=value2"\n}\n'

• 如果需要使用POST方法在请求主题中发送查询参数，可以将参数编码后作为可选参数提供给urlopen()函数

from urllib import request,parse
url = 'http://httpbin.org/post'
parms = {
    'name1':'value1',
    'name2':'value2'
}
qs = parse.urlencode(parms)
u = request.urlopen(url,qs.encode("ascii"))
resp = u.read()
print(resp)

• 返回值如下

~/ning-dashboard/tmp > python3 ttt.py                                                                                      13s
b'{\n  "args": {}, \n  "data": "", \n  "files": {}, \n  "form": {\n    "name1": "value1", \n    "name2": "value2"\n  }, \n  "headers": {\n    "Accept-Encoding": "identity", \n    "Content-Length": "25", \n    "Content-Type": "application/x-www-form-urlencoded", \n    "Host": "httpbin.org", \n    "User-Agent": "Python-urllib/3.7", \n    "X-Amzn-Trace-Id": "Root=1-6298df7a-572e0ce9697610826d3e8807"\n  }, \n  "json": null, \n  "origin": "210.22.74.111", \n  "url": "http://httpbin.org/post"\n}\n'

• 如果想在发出的请求中提供一些自定义的http头，比如修改user-agent字段，那么可以创建一个包含字段值的字典，并创建一个request实例，然后将其传给urlopen(),

from urllib import request,parse
url = 'http://httpbin.org/post'
parms = {
    'name1':'value1',
    'name2':'value2'
}
headers ={
    'User-agent':'none/ofyourbusiness',
    'Spam':'Eggs'
}
qs = parse.urlencode(parms)
req = request.Request(url,qs.encode("ascii"),headers=headers)
u = request.urlopen(req)
resp = u.read()
print(resp)

• 返回值

~/ning-dashboard/tmp > python3 ttt.py                                                                                   2m 18s
b'{\n  "args": {}, \n  "data": "", \n  "files": {}, \n  "form": {\n    "name1": "value1", \n    "name2": "value2"\n  }, \n  "headers": {\n    "Accept-Encoding": "identity", \n    "Content-Length": "25", \n    "Content-Type": "application/x-www-form-urlencoded", \n    "Host": "httpbin.org", \n    "Spam": "Eggs", \n    "User-Agent": "none/ofyourbusiness", \n    "X-Amzn-Trace-Id": "Root=1-6298e1cb-2cec587f0550b28d35dff7ec"\n  }, \n  "json": null, \n  "origin": "210.22.74.111", \n  "url": "http://httpbin.org/post"\n}\n'

• 也可以尝试使用requests模块

import requests
url = 'http://httpbin.org/post'

parms = {
    'name1':'value1',
    'name2':'value2'
}
headers ={
    'User-agent':'none/ofyourbusiness',
    'Spam':'Eggs'
}

resp = requests.post(url,data=parms,headers=headers)
print(resp.text)

• 返回结果

~/ning-dashboard/tmp > python3 ttt.py                                                                                      20s
{
  "args": {},
  "data": "",
  "files": {},
  "form": {
    "name1": "value1",
    "name2": "value2"
  },
  "headers": {
    "Accept": "*/*",
    "Accept-Encoding": "gzip, deflate",
    "Content-Length": "25",
    "Content-Type": "application/x-www-form-urlencoded",
    "Host": "httpbin.org",
    "Spam": "Eggs",
    "User-Agent": "none/ofyourbusiness",
    "X-Amzn-Trace-Id": "Root=1-6298e122-393530d343acb327131bcca8"
  },
  "json": null,
  "origin": "210.22.74.111",
  "url": "http://httpbin.org/post"
}