Example for Medium article "Python Decorators Explained"

basic_decorator.py

def decorate(func):
    print("Do something before func()")
    func()
    return func #return the original function, unmodified

@decorate
def hello():
    print("Hello, world!")

decorator_example.py

import urllib.request, json 

class XKCDThing(object):
    def __init__(self):
        self.subscribers = []

    def subscriber(self, func):
        self.subscribers.append(func)
        return func

    def publish(self, title, link):
        for func in self.subscribers:
            func(title, link)

    def run(self):
        url = "https://xkcd.com/info.0.json"
        with urllib.request.urlopen(url) as req:
            data = json.loads(req.read().decode())
            title = data['safe_title']
            link = data['img']
            self.publish(title, link)


app = XKCDThing()

@app.subscriber
def eventHandler1(title, link):
    print("Event handler 1 called!")
    print(f"Title: {title}")

@app.subscriber
def eventHandler2(title, link):
    print("Event handler 2 called!")
    print(f"Link: {link}")

app.run()

wrapper_decorator.py

def wrap(func):
    def wrapper():
        print("Say hello? Y/N")
        if input() == "Y":
            func()
        else:
            print("OK.")
    return wrapper

@wrap
def hello():
    print("Hello, world!")
hello()