decorator_deprecated.py

from functools import wraps
import warnings


def deprecated(func):
    code = func.__code__
    warnings.warn_explicit(
        func.__name__ + 'is deprecated',
        category=DeprecationWarning,
        filename=code.co_filename,
        lineno=code.co_firstlineno + 1)
    return func

decorator_once.py

from functools import wraps


def once(func):
    @wraps(func)
    def inner(*args, **kwargs):
        if not inner.called:
            result = func(*args, ** kwargs)
            inner.called = True
            return result
    inner.called = False
    return inner

decorators_contracts.py

from functools import wraps


# more contracts https://pypi.org/project/contracts/
def pre(condition, message):
    def wrapper(func):
        @wraps(func)
        def inner(*args, **kwargs):
            assert condition(*args, **kwargs), message
            return func(*args, **kwargs)
        return inner
    return wrapper

logger_decorator.py

from functools import wraps


def logger(filename):
  def decorator(func):
    @wraps(func)
    def wrapped(*args, **kwargs):
        result = func(*args, **kwargs)
        with open(filename, 'w') as f:
            f.write(str(result))
        return result
    return wrapped
return decorator

wait_decorators.py

from functools import wraps
import random
import time

def wait_random(min_wait=1, max_wait=30):
    def inner_function(func):
         @wraps(func)
        def wrapper(args, **kwargs):
            time.sleep(random.randint(min_wait, max_wait))
            return func(args, **kwargs)

        return wrapper

    return inner_function