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From: Terry Reedy <tjreedy@udel.edu>
Subject: Re: Tuple of lists concatenation  -  function vs comprehension
Date: Sun, 07 Dec 2014 17:21:37 -0500
References: <001a01d0122f$86b95480$942bfd80$@gmail.com> <20141207151749.GB32773@FuzzyHorror> <001b01d01232$77700840$665018c0$@gmail.com>
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On 12/7/2014 10:28 AM, Ivan Evstegneev wrote:
> Hi Shiyao,
>
> Now I see, that it was kind of dumb question...
>
>>>>> x = ([1, 2], [3, 4], [5, 6])
>>>>> L = []
>>>> [L.extend(i) for i in x]
> [None, None, None]

Using a list comprehension for the expression side-effect, when you do 
not actually want the list produced by the comprehension, is considered 
bad style by many.  There is nothing wrong with explicit loops.

> BUT when I check L itself I'll see this one
>
>>>> L
> [1,2,3,5,6]


-- 
Terry Jan Reedy