python decorator

1def our_decorator(func):
2    def function_wrapper(x):
3        print("Before calling " + func.__name__)
4        func(x)
5        print("After calling " + func.__name__)
6    return function_wrapper
7
8@our_decorator
9def foo(x):
10    print("Hi, foo has been called with " + str(x))
11
12foo("Hi")
13

1#Decorator are just function that take function as first
2#parameter and return a function
3def logging(f):
4  def decorator_function(*args, **kwargs):
5    print('executing '+f.__name__)
6    return f(*args, **kwargs)
7  return decorator_function
8#Use it like this
9@logging
10def hello_world():
11  print('Hello World')
12#calling hello_world() prints out:
13#executing hello_world
14#Hello World

1# Decorator with arguments
2import functools
3
4# First function takes the wanted number of repetition
5def repeat(num_times):
6    # Second function takes the function
7    def decorator_repeat(func):
8        # Third function, the wrapper executes the function the number of times wanted        
9        # functools decorator to print the true name of the function passed instead of "wrapper"
10        @functools.wraps(func)
11        def wrapper(*args, **kwargs):
12            for _ in range(num_times):
13                result= func(*args, **kwargs)
14            return result
15        return wrapper
16    return decorator_repeat
17
18# Our function using the decorator
19@repeat(num_times= 3)
20def greet(name):
21    print(f"Hello {name}")
22
23greet("thomas")

1import functools
2
3# A decorator is a Higher order function "_with_logging"
4# It takes the function to be decorated as its argument
5# In order to pass in some arbitrary arguments, it must be wrapped into
6# another HOF (Higher order function) that will receive the inputs
7def with_logging(level=logging.DEBUG, msg = None):
8    def _with_logging(fn):
9        # 'wraps' is a HOF that will give fn's name and docs to decorated_fn i.e. 
10        #   decorated_fn.__name__ = fn.__name__
11        #   help(decorated_fn) = help(fn)
12        @functools.wraps(fn)
13        def decorated_fn(*args, **kwargs):
14            res = fn(*args, **kwargs)
15            print("\n***************", f"\n{msg}", "\nExecuting with Args: ", *args, **kwargs)
16            logging.log(level, res)
17            return res
18        return decorated_fn
19    return _with_logging
20  
21# Used this way
22@with_logging(level=logging.DEBUG, msg="Some awesome comment")
23def hello_world(name):
24  return f'Hello World {name}'
25  
26# Results after calling hello_world("John")
27#
28# ***************
29# Some awesome comment
30# Executing with Args: John
31# Hello World John
32

1def deco(func):
2    def wrap(lst):
3        x = [1 if i % 2 == 0 else 0 for i in lst]
4        return x
5        func(lst)
6    return wrap
7
8@deco  

1from functools import wraps
2def debug(func):
3    @wraps(func)
4    def out(*args, **kwargs):
5        print('hello world')
6        return func(*args, **kwargs)
7    return out
8
9@debug
10def add(x, y):
11    return x + y