Flask 路由 route

转载 http://python.jobbole.com/80956/
有原文https://ains.co/blog/things-which-arent-magic-flask-part-1.html

python简单装饰器

# This is our decorator
def simple_decorator(f):
    # This is the new function we're going to return
    # This function will be used in place of our original definition
    def wrapper():
        print "Entering Function"
        f()
        print "Exited Function"

    return wrapper

@simple_decorator 
def hello():
    print "Hello World"

hello()

运行上述代码会输出以下结果：

Entering Function
Hello World
Exited Function

带参数的装饰器

def decorator_factory(enter_message, exit_message):
    # We're going to return this decorator
    def simple_decorator(f):
        def wrapper():
            print enter_message
            f()
            print exit_message

        return wrapper

    return simple_decorator

@decorator_factory("Start", "End")
def hello():
    print "Hello World"

hello()

u结果
Start
Hello World
End

j简单实现Flask 路由

class NotFlask():
    def __init__(self):
        self.routes = {}

    def route(self, route_str):
        def decorator(f):
            self.routes[route_str] = f
            return f

        return decorator

    def serve(self, path):
        view_function = self.routes.get(path)
        if view_function:
            return view_function()
        else:
            raise ValueError('Route "{}"" has not been registered'.format(path))


app = NotFlask()

@app.route("/")
def hello():
    return "Hello World!"

print app.serve("/")

u结果
Hello World!