Python - third party HTTP library requests usage details 1 (installation configuration, basic usage)

One 、 Basic introduction

1, What is? Requests library ？

（1） Requests Yes, it is python Language based urllib Compiling , It's using Apache2 Licensed Open source protocol HTTP library . （2） Requests Compared with urllib Concise and many , It can be said that at present Python The easiest to implement HTTP library .

2,Requests Library feature

• Keep-Alive & Connection pool
• International domain names and URL
• With lasting Cookie Conversation
• Browser style SSL authentication
• Automatic content decoding
• basic / Abstract authentication
• elegant key/value Cookie
• Automatically decompress
• Unicode Response body
• HTTP(S) Agent support
• Upload files in blocks
• Stream download
• Connection timeout
• Block request
• Support .netrc

3, install Requests library

（1） because Requests It's a third party library , Therefore, the following commands should be executed in the terminal before use pip install ：

pip install requests

（2） Because of my Mac The computer is equipped with the latest Python 3.7 edition （ Alias python3）, It comes with it pip, So execute the following command to install ：

python3 -m pip install requests

Two 、 Basic usage

1, Send a request

Requests It provides us with various ways to request ：

import requests
requests.get('https://api.github.com/events')
requests.post("http://httpbin.org/post")
requests.put("http://httpbin.org/put")
requests.delete("http://httpbin.org/delete")
requests.head("http://httpbin.org/get")
requests.options("http://httpbin.org/get")

2, Pass parameters

（1） If you need to pass parameters , We can splice the parameters directly into   URL Back ：

requests.get('http://httpbin.org/get?name=hangge.com&age=100')

（2） You can also use params Keyword passes a dictionary in as a parameter （ Parameters will also be automatically spliced to URL Back ）：

import requests
data = {
"name": "hangge.com",
"age": 100
}
response = requests.post('http://httpbin.org/post', params=data)
print(response.text)

（3） If you use data Keyword passes a dictionary in as a parameter , Parameters will be passed in the form of a form （ Parameters will not be spliced to URL Back ）：

import requests
data = {
"name": "hangge.com",
"age": 100
}
response = requests.post('http://httpbin.org/post', data=data)
print(response.text)

（4） Sometimes the data we want to send doesn't need to be submitted in form . Like passing on a string Type of JSON strand , have access to json Parameters to transmit ：

import requests
data = {
"name": "hangge.com",
"age": 100
}
response = requests.post('http://httpbin.org/post', json=data)
print(response.text)

3、 ... and 、 In response to the results

1, Get response content

（1） When using Requests When making a network request , Will return a Response object , We can use it to get the response content ：

import requests
response = requests.get("https://www.baidu.com")
print("\n--- type(response) ---\n", type(response))
print("\n--- response.status_code ---\n", response.status_code) # Response status code
print("\n--- response.cookies ---\n", response.cookies) #Cookie
print("\n--- type(response.text) ---\n", type(response.text))
print("\n--- response.text ---\n", response.text) # Response text content
print("\n--- response.content ---\n", response.content)

（2） In many cases, if you directly output   response.text There will be garbled problems （ See above ）, There are two ways to solve this problem ：

• First, use. response.content Get the binary response content , And then through decode() Convert to utf-8.

import requests
response = requests.get("https://www.baidu.com")
print(response.content.decode("utf-8"))

• Second, it can be used response.encoding Property to specify the response encoding to use ：

import requests
response = requests.get("https://www.baidu.com")
response.encoding="utf-8"
print(response.text)

Either way above , You can see that the problem of garbled code has been solved ：

2,JSON Response content

（1） If the request returns JSON Formatted data , have access to Requests Built in JSON decoder , It can help us deal with JSON data ：

import requests
response = requests.get('http://httpbin.org/get?name=hangge.com&age=100')
json = response.json()
print(json)
print(json['args']['name'])

（2） Of course we can use it json.loads() Method manually json The string is converted to dict Dictionaries , The effect of the following code is the same as that of the above ：

import requests
import json
response = requests.get("http://httpbin.org/get?name=hangge.com&age=100")
json = json.loads(response.text)
print(json)
print(json['args']['name'])