John Salerno wrote:
> But why does the documentation say "The return value of the decorator
> need not be callable"?
The thing returned by a decorator does not need to be callable, but if you
want to call it, then it better be!
This is no different from this:
my_func = "hello world"
my_func() # fails because strings aren't callable
So if I do this:
def decorator(func):
# ignores the function and returns a string
return "hello world"
@decorator
def my_func():
x = 1
y = 2
return x+y
print(my_func) # prints "hello world"
my_func() # fails because strings aren't callable
If that's useful to you, decorator syntax allows it. That is all the
documentation means.
> And why, if I remove the decorator and just
> leave the two functions as if, does the call to move(roll_die()) work?
> Isn't that what the decorator syntax is essentially doing?
The call move(roll_die()) is similar to this:
temp = roll_die()
my_string = move(temp)
which is perfectly fine, because you never call my_string. If you did, you'd
get the same error, because strings aren't callable.
The decorator syntax is completely different. It is doing this:
# replace the function roll_die with the output of move, which is a string
roll_die = move(roll_die)
# now try to call "roll_die", actually a string
roll_die()
which is more like:
move(roll_die)()
See the difference?
--
Steven
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