Python.Requests库的基本使用

Requests安装#

使用pip安装命令：

pip install requests

打开cmd，输入python然后导入requests如果安装成功没有任何提示

如果提示如下则说明安装失败

ImportError: No module named 'requests'

Requests 基础应用#

发送不同类型HTTP请求#

requests库内置了不同的方法来发送不同类型的http请求，用法如下所示：

import requests

base_url = "http://httpbin.org"

# 发生GET类型请求
r_get = requests.get(base_url + "/get")
print(r_get.status_code)

# 发生POST类型请求
r_post = requests.post(base_url + "/post")
print(r_post.status_code)

# 发生PUT类型请求
r_put = requests.put(base_url + "/put")
print(r_put.status_code)

# 发生DELETE类型请求
r_delete = requests.delete(base_url + "/delete")
print(r_delete.status_code)

执行结果，200是状态码表示发送请求成功

参数传递

传递URL参数

一般在GET请i去中使用字符串（query string）来进行参数传递，在requests库中使用方法如下：

param_data = {'hero': 'leesin'}
r_data = requests.get(base_url + '/get', params=param_data)
print(r_data.url)
print(r_data.status_code)

执行结果

http://httpbin.org/get?hero=leesin
200

传递body参数#

在post请求中，一般参数都在请求体（Request body）中传递，在Requests中用法如下：

form_data = {'hero': 'leesin'}
r_body = requests.post(base_url + '/post', data=form_data)
print(r_body.text)

执行结果

{
  "args": {}, 
  "data": "", 
  "files": {}, 
  "form": {
    "hero": "leesin"
  }, 
  "headers": {
    "Accept": "*/*", 
    "Accept-Encoding": "gzip, deflate", 
    "Content-Length": "11", 
    "Content-Type": "application/x-www-form-urlencoded", 
    "Host": "httpbin.org", 
    "User-Agent": "python-requests/2.22.0"
  }, 
  "json": null, 
  "origin": "61.144.173.21, 61.144.173.21", 
  "url": "https://httpbin.org/post"
}

请求头定制#

如果你想为请求添加HTTP头部，只要简单传递一个dict给headers参数就可以了。
用法如下：

form_data = {'hero': 'leesin'}
header = {'user-agent': 'Mozilla/5.0'}
r_headers = requests.post(base_url + '/post', data=form_data, headers=header)
print(r_headers.text)

返回值

{
  "args": {}, 
  "data": "", 
  "files": {}, 
  "form": {
    "hero": "leesin"
  }, 
  "headers": {
    "Accept": "*/*", 
    "Accept-Encoding": "gzip, deflate", 
    "Content-Length": "11", 
    "Content-Type": "application/x-www-form-urlencoded", 
    "Host": "httpbin.org", 
    "User-Agent": "Mozilla/5.0"
  }, 
  "json": null, 
  "origin": "61.144.173.21, 61.144.173.21", 
  "url": "https://httpbin.org/post"
}

响应内容#

当请求发送成功之后，我们可以获取响应内容。如响应状态码，响应头信息，响应体内容

form_data = {'hero': 'leesin'}
header = {'user-agent': 'Mozilla/5.0'}
r_response = requests.post(base_url + '/post', data=form_data, headers=header)

# 获取响应状态码
print(r_response.status_code)

# 获取响应头信息
print(r_response.headers)

# 获取响应内容
print(r_response.text)

# 将响应内容以json格式返回
print(r_response.json())

返回值

200
{'Access-Control-Allow-Credentials': 'true', 'Access-Control-Allow-Origin': '*', 'Content-Encoding': 'gzip', 'Content-Type': 'application/json', 'Date': 'Fri, 28 Jun 2019 14:38:09 GMT', 'Referrer-Policy': 'no-referrer-when-downgrade', 'Server': 'nginx', 'X-Content-Type-Options': 'nosniff', 'X-Frame-Options': 'DENY', 'X-XSS-Protection': '1; mode=block', 'Content-Length': '258', 'Connection': 'keep-alive'}
{
  "args": {}, 
  "data": "", 
  "files": {}, 
  "form": {
    "hero": "leesin"
  }, 
  "headers": {
    "Accept": "*/*", 
    "Accept-Encoding": "gzip, deflate", 
    "Content-Length": "11", 
    "Content-Type": "application/x-www-form-urlencoded", 
    "Host": "httpbin.org", 
    "User-Agent": "Mozilla/5.0"
  }, 
  "json": null, 
  "origin": "61.144.173.21, 61.144.173.21", 
  "url": "https://httpbin.org/post"
}

{'args': {}, 'data': '', 'files': {}, 'form': {'hero': 'leesin'}, 'headers': {'Accept': '*/*', 'Accept-Encoding': 'gzip, deflate', 'Content-Length': '11', 'Content-Type': 'application/x-www-form-urlencoded', 'Host': 'httpbin.org', 'User-Agent': 'Mozilla/5.0'}, 'json': None, 'origin': '61.144.173.21, 61.144.173.21', 'url': 'https://httpbin.org/post'}