So, I was studying the FLASK framework in python and made my very first simple program and by default I've seen people using app = Flask(__name__) and just below that line they use the decorator @app.route("/"),So I thought that what would happen if I change the name of the variable to something else? Like in the code below I've changed it to something = Flask(__name__) so now I'm confused that how does it still work when I decorate the function index() with @something.route("/") ,is the name of the decorator function defined in FLASK changing dynamically? and if so how can I make my own decorators like this so that they too change their names dynamically?
from flask import Flask
something = Flask(__name__)
@something.route("/")
def index():
return "Hello, World!"
Decorator is just a syntactic sugar:
def decorator(func):
pass
@decorator
def decorated():
pass
is the same as:
def decorator(func):
pass
def decorated():
pass
decorated = decorator(decorated)
The decorator name is nothing more than a function that accepts one argument. You could even use print function as a decorator. Any valid callable will do:
@print
def index():
pass
Obviously that makes little sense, because:
def index():
pass
index = print(index)
Anyway that's how this could be implemented in flask
class Flask:
def route(self, url):
def wrapper(func):
# register route for url
return func
return wrapper
something = Flask()
@something.route("/")
def index():
pass
something.route("/") is a function call that returns the real decorator which is actually the inner function named wrapper.
So you can even do something like this:
something_route_index = something.route("/")
@something_route_index
def index():
pass