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in Technique[技术] by (71.8m points)

lambda function don't closure the parameter in Python?

Code talks more:


from pprint import pprint

li = []

for i in range(5):
        li.append(lambda : pprint(i))

for k in li:
        k()

yield:

4
4
4
4
4

why not

0
1
2
3
4

??

Thanks.

P.S. If I write the complete decorator, it works as expected:



from pprint import pprint

li = []

#for i in range(5):
        #li.append(lambda : pprint(i))

def closure(i):
        def _func():
                pprint(i)
        return _func

for i in range(5):
        li.append(closure(i))

for k in li:
        k()
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1 Reply

0 votes
by (71.8m points)

you need to do:

lambda i=i: pprint(i)

instead to capture the current value of i


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