How the return result like this , What is the lambda function do in this code?

Question

flist = []

for i in range(3):

    flist.append(lambda: i)

for f in flist:
    print f()

I don't know why its returning 2,2,2

Answer 1

In the last iteration through the first loop, your i value is 2 and hence ALL the i values in each element of the list are now 2. This is because you have created a live reference to the i variable.

Here is a simplified demonstration:

a = 5
c = lambda: a
a += 5
>>> c()
10