decorator.py - Pasteur

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#!/usr/bin/env python

# pylint:disable=missing-module-docstring
# pylint:disable=missing-function-docstring

import inspect

#
# Simple decorator
#

def simple_decorator(func):
    def wrapper(*args, **kwargs):
        print('{{ wrapper()')
        result = func(*args, **kwargs)
        print('}}\n')
        return result

    return wrapper

# The following:
@simple_decorator
def do_something_1():
    print(inspect.currentframe().f_code.co_name)

# Is the same as:
def do_something_2():
    print(inspect.currentframe().f_code.co_name)
do_something_2 = simple_decorator(do_something_2)


#
# Parameterized decorator (a function that returns a decorator)
#

def parameterized_decorator(param=1337, other=13.37):
    def decorator(func):
        def wrapper(*args, **kwargs):
            print('{{ wrapper(param=%s, other=%s)' % (param, other))
            result = func(*args, **kwargs)
            print('}}\n')
            return result

        return wrapper

    return decorator

# The following:
@parameterized_decorator()      # Note the `()` - this is a "decorator-decorator"
def do_something_3():
    print(inspect.currentframe().f_code.co_name)

# Is the same as:
def do_something_4():
    print(inspect.currentframe().f_code.co_name)
do_something_4 = parameterized_decorator()(do_something_4)


#
# Parameterized decorator with defaults, working in mixed mode
#

def mixed_decorator(param=1337, other=13.37):
    def decorator(func):
        def wrapper(*args, **kwargs):
            print('{{ wrapper(param=%s, other=%s)' % (param, other))
            result = func(*args, **kwargs)
            print('}}\n')
            return result

        return wrapper

    # Basically, if first parameter is a function, and all other parameters are equal to their default values,
    # one can assume that the decorator has been (mistakenly?) used in the code as:
    #   @mixed_decorator            # no `()`
    #   def foo():
    if callable(param) and other == 13.37:
        func, param = param, 1337
        return decorator(func)

    return decorator

@mixed_decorator
def do_something_5():
    print(inspect.currentframe().f_code.co_name)

@mixed_decorator()
def do_something_6():
    print(inspect.currentframe().f_code.co_name)


#
# Test this shit
#

do_something_1()
do_something_2()
do_something_3()
do_something_4()
do_something_5()
do_something_6()