The Best* Python Cheat Sheet
kieranholland.com
kieranholland.com
A decorator is a callable that manipulates and returns a function.
# wraps decorator copies metadata of decorated function (func) to wrapped function (out)
from functools import wraps
def show_call(func):
"""
Print function name and arguments each time it is called.
"""
@wraps(func)
def out(*args, **kwds):
print(func.__name__, args, kwds)
return func(*args, **kwds)
return out
@show_call
def add(x, y):
return x + y
I couldn't have thought of a worse example for a cheat sheet.
A cheat sheet is supposed to give short simple explanations/demonstrations.
That example shouldn't have a nested function, it should demonstrate just 1 decorator function and 1 decorated function and none of these functions should be nested and they also shouldn't use arguments with asterisks (if possible).
Feedback from someone still failing to understand what decorator is, especially after reading the cheat sheet.
Wrapping the inner function of the decorator with @wraps is quite common - one might consider it a bug in the language that the @wraps feature is not built into the decorator mechanism.
But it is a valid point that decorators should not be presented that early.
The decorator syntax itself is just simple syntax sugar for replacing the decorated function (add) with the return value of the decorator function (show_call). The example is essentially equivalent to this:
def show_call(func):
...
def add(x, y):
return x + y
add = show_call(add)
def decorate(<decorator args>):
def _decorate(<thing to be decorated>):
pass
return _decorate
@decorate(foo=1)
def myfunc():
passDesign principles:
• Focus on Python core
• Comprehensive but selective (Just what you need)
• Densely packed
• Well-linked
• Linkable
• Responsive
• Printable
*It may not be the best Python cheat sheet, but it aspires to be.
<link href="https://fonts.googleapis.com/css2?family=Roboto+Mono:ital,wght@0,100..700;1,100..700&display=swap" rel="stylesheet">Also, you described "s.rstrip" twice