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From: dieter <dieter@handshake.de>
Newsgroups: comp.lang.python
Subject: Re: What does a list comprehension do
Date: Thu, 26 Nov 2015 08:17:43 +0100
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Antoon Pardon <antoon.pardon@rece.vub.ac.be> writes:

> Op 20-11-15 om 08:49 schreef dieter:
>> In addition, the last few days have had two discussions in this list
>> demonstrating the conceptial difficulties of late binding -- one of them:
>>
>>       Why does "[lambda x: i * x for i in range(4)]" gives
>>       a list of essentially the same functions?
>
> Can you (or someone else) explain what a list comprehension is equivallent of.
> Especially in python3.

I am not sure about "Python3" (never used it), but in Python 2,
the simple list comprehension "[x for x in l]" is roughly equivalent to:

    result = []
    for x in l: result.append(x)
    ... the list comprehension result is in "result" which (however) is not bound ...

In Python 3, "x" might not be bound as well - to harmonise list comprehension
with generator expressions (and avoid the confusion, that a local
(temporary) binding can change the value of a global binding).