List comprehension + lambdas - strange behaviour

[Emile van Sebille]

On 5/6/2010 12:34 PM Artur Siekielski said...
> Hello.
> I found this strange behaviour of lambdas, closures and list
> comprehensions:
>
>>>> funs = [lambda: x for x in range(5)]

funs is now a list of lambda functions that return 'x' (whatever it 
currently is from whereever it's accessible when invoked)



 >>> [f() for f,x in zip(funs,range(5))]
[0, 1, 2, 3, 4]
 >>> del x
 >>> [f() for f in funs]
Traceback (most recent call last):
   File "<stdin>", line 1, in ?
   File "<stdin>", line 1, in <lambda>
NameError: global name 'x' is not defined
 >>>

Emile