How to change a function's return using a decorator?

Question

I want create a decorator to change a function's return value like that, How to do that like below?:

def dec(func):
    def wrapper():
        #some code...
        #change return value append 'c':3
    return wrapper

@dec
def foo():
    return {'a':1, 'b':2}

result = foo()
print result
{'a':1, 'b':2, 'c':3}

Answer 1

Well.... you call the decorated function and change the return value:

def dec(func):
    def wrapper(*args, **kwargs):
        result = func(*args, **kwargs)
        result['c'] = 3
        return result
    return wrapper