Flask入门及登录应用

入门

安装

pip install -i http://pypi.douban.com/simple --trusted-host pypi.douban.com 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
  
  ")
      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

登录成功将跳转至百度页面

信息显示

显示详细信息

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_info'] = user

@app.route('/index', methods=['GET'])
def index():
    user = session.get('user_info')
    if not user:
        return redirect('/login')
    return render_template('index.html', user_dict=USERS)

反向生成URL

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

@app.route('/index', methods=['GET'])
def index():
    user = session.get('user_info')
    if not user:
        url =url_for('n1')
        return redirect(url)
    return render_template('index.html', user_dict=USERS)

@app.route('/login', methods=['GET', 'POST'], endpoint='n1')
def login():
	if request.method == 'GET':
        return render_template('login.html')
....

应用demo总结

• 示例
• 装饰器：用户认证
  • 装饰器
  • 多个装饰器
  • 反向查找的名称不允许重复：endpoint