Flask入门及登录应用

入门

安装

pip install flask

wsgi

• werkzeug 示例

  from werkzeug.wrappers import Request, Response
  
  @Request.application
  def hello(request):
      return Response('Hello World!')
  
  if __name__ == '__main__':
      from werkzeug.serving import run_simple
      run_simple('localhost', 4000, hello)
  

• wsgiref 示例

  from wsgiref.simple_server import make_server
  
  def runserver(environ, start_response):
      start_response('200 OK', [('Content-Type', 'text/html')])
      return [bytes('<h1>Hello, web!</h1>', encoding='utf-8'), ]
  
  if __name__ == '__main__':
      # obj = WSGIHandler()
      httpd = make_server('', 8000, runserver)
      httpd.serve_forever()
  

• 本质的本质

  import socket
  
  def handle_request(client):
      buf = client.recv(1024)
      client.send("HTTP/1.1 200 OK\r\n\r\n")
      client.send("Hello, Seven")
  
  def main():
      sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
      sock.bind(('localhost',8000))
      sock.listen(5)
  
      while True:
          connection, address = sock.accept()
          handle_request(connection)
          connection.close()
  
  if __name__ == '__main__':
  	main()
  

基本使用

from flask import Flask

# 实例化 Flask 对象
app = Flask(__name__)

# 将 '/' 和 函数index的对应关系添加到路由中
@app.route('/')		# 1. v = app.route('/')   2. v(index)
def index():
    return 'Hello World!'
 
if __name__ == '__main__':
    # 监听用户请求
    # 如果有用户到来，执行app的__call__方法
    app.run()

应用demo

登录

登录成功将跳转至 index 页面

登录成功之后才能访问，所以需要引入 session

# 在登录函数中添加 session
if user == 'qiu' and pwd == '123':
    session['user'] = user

@app.route('/index')
def index():
    user = session.get('user')
    if not user:
        return redirect('/login')
    return render_template('index.html')

Django 中 session 的数据放在数据库，但是这里没有连接数据库，这里是放在加密的 cookie 中，但是只加 session 是报错的

RuntimeError: The session is unavailable because no secret key was set.

需要设置 secret key，相当于加密时的 “加盐”

from flask import Flask, render_template, request, redirect, session

app = Flask(__name__)
app.secret_key = 'dsadaf'

@app.route('/login', methods=['GET', 'POST'])
...