Flask中特殊装饰器的使用

import apps
from flask import request, session, redirect
 
app = apps.create_app() 
 
@app.before_request
def before1():
    print("before1", request)
  
@app.before_request
def before2():
    print("before2")
    if request.path == "/":
        return None
    else:
        #这里抛出了一个异常，会被@app.errorhandler(Exception)
        # 捕获到。
        raise Exception("hahaha") 
 
@app.before_request
def before3():
    print("before3")
  
@app.after_request
def after1(res):
    print("after1")
    return res 
 
@app.after_request
def after2(res):
    print("after2")
    return res 
 
@app.after_request
def after3(res):
    print("after3")
    return res
  
# 处理异常，接受参数，可以重定向到指定页面
@app.errorhandler(Exception)
def error(e):
    print("error")
    return redirect("/") 
 
@app.route("/login")
def login():
    print("login")
    return "login"
 
@app.route('/')
def hello_world():  # put application's code here
    return 'Hello World!'
 
if __name__ == '__main__':
    app.run()