While I was investigating a problem I had with lexical closures in Javascript code, I came along this problem in Python:

    flist = []
    
    for i in xrange(3):
        def func(x): return x * i
        flist.append(func)
    
    for f in flist:
        print f(2)

Note that this example mindfully avoids `lambda`. It prints &quot;4 4 4&quot;, which is surprising. I&#39;d expect &quot;0 2 4&quot;. 

This equivalent Perl code does it right:

    my @flist = ();
    
    foreach my $i (0 .. 2)
    {
        push(@flist, sub {$i * $_[0]});
    }
    
    foreach my $f (@flist)
    {
        print $f-&gt;(2), &quot;\n&quot;;
    }

&quot;0 2 4&quot; is printed.

Can you please explain the difference ?


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Update: 

The problem **is not** with `i` being global. This displays the same behavior:

    flist = []
    
    def outer():
        for i in xrange(3):
            def inner(x): return x * i
            flist.append(inner)
    
    outer()
    #~ print i   # commented because it causes an error
    
    for f in flist:
        print f(2)

As the commented line shows, `i` is unknown at that point. Still, it prints &quot;4 4 4&quot;.





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