Flask学习笔记11之特殊的装饰器

1. before_request

2. after_request

3. before_first_request

4. template_global

5. template_filter

6. errorhandler

from flask import Flask

app = Flask(__name__)
app.debug = True
app.secret_key = 'flask'


@app.before_request
def before():
    print('before request')


@app.after_request
def after(response):
    """
    装饰器after_request： 必须接收参数，而且还要有返回值
    :param response:
    :return:
    """
    print('after request')
    return response


@app.route('/r')
def test_before_after_request():
    print('test_before_after_request')
    return 'test_before_after_request'


if __name__ == '__main__':
    app.run()

before request
test_before_after_request
after request

如果定义多个before_request 装饰器，谁先定义，谁先执行

如果定义多个after_request 装饰器，谁先定义，谁后执行

before_first_request ： 第一次请求才会执行，后面的请求都不会执行

@app.errorhandler(404)
def error_handler(arg):
    print(arg)
    return '请求视图有误'