Summary: Flask web is a micro frame. "Micro" does not mean Flask function is not strong. Micro framework of the "micro" word indicates Flask goal is to keep the core simple and scalable.
A, Flask installation
pip install flask
Second, create a project Flask
- First, we imported the Flask class.
- Examples of the class created app, the first parameter is the name of the application or the module package. If you use a single module, you should use _ name _.
- Using the route () decorator to bind URL function.
Example:
from flask import Flask
from flask import request
app = Flask(__name__)
@app.route('/study', methods=['GET'])
def hello_world():
return 'Hello World!'
@app.route('/study/<username>', methods=['GET'])
def studyvariable(username):
print(request.method)
print(request.url)
return 'Hello, {}'.format(username)
@app.route('/study/studypost', methods=['POST'])
def study_post():
data = request.form
print(type(data))
print(data)
print(data['username'])
return 'ok'
if __name__ == '__main__':
app.run()
Third, the correlation method, the object
（1）app.route(rule, options)
- rule parameter indicates the URL binding and function.
- options is a list of parameters to be forwarded to the underlying Rule objects.
- methods received is a list: GET, POST etc.
(2) app.run (Host, Port, Debug, Options) (All parameters are optional)
- host: To monitor the host name, the default is 127.0.0.1
- port: the port number is provided, the default value is 5,000
- debug: Debugging is turned on, the default is false . If set to true, the debug information provided
- options: to be forwarded to the underlying Werkzeug server.
（3）request
- In Flask global objects by providing request information to the request, the operation request data
(4) variable rules
by the URL is part of the tag <variable_name> can add variables in the URL. Labeled moiety as keyword arguments passed to the function. By using the <converter: variable_name>, you can selectively add a converter, a variable designated rule. Variables such as the example "<username>"
- Converter type:
| Types of | description |
|---|---|
| string | (Default value) accept any text that does not contain a slash |
| int | Receiving a positive integer |
| float | Receiving positive float |
| path | Similar string, but it may contain slashes |
| uuid | Accept the UUID string |
Fourth, debugging project
- Console output after starting the project:
FLASK_APP = app.py
FLASK_ENV = development
FLASK_DEBUG = 0
In folder F:/Python项目/untitled
F:\Python项目\untitled\venv\Scripts\python.exe -m flask run
* Serving Flask app "app.py"
* Environment: development
* Debug mode: off
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
- By Postman debugging
Sending a Get request: http: //127.0.0.1: 5000 / study / wangwu
response: Hello, wangwu
Console output:
127.0.0.1 - - [25/Feb/2020 14:13:15] "GET /study/wangwu HTTP/1.1" 200 -
GET
http://127.0.0.1:5000/study/wangwu
Post send request: http: //127.0.0.1: 5000 / study / studypost
form data: { 'username': 'lisi ', 'password': '123456'}
Response: ok
Console output:
<class 'werkzeug.datastructures.ImmutableMultiDict'>
ImmutableMultiDict([('username', 'lisi'), ('password', '123456')])
lisi
127.0.0.1 - - [25/Feb/2020 14:26:42] "POST /study/studypost HTTP/1.1" 200 -
