List comprehensions' ugliness (Was: Re: How to explain exactly what "def" does?)

Donnal Walter donnal at
Thu Feb 6 10:46:27 CET 2003

Alex Martelli wrote:
> Hans Nowak wrote:
>    ...
>>   [mylist.append(z) for z in otherlist]
>>The point of list comprehensions is to return a list, and the example
>>above doesn't do anything with that list.  It's better written as
>>   for z in otherlist:
>>       mylist.append(z)
> mylist.extend(otherlist) is better.

mylist = mylist + otherlist

The above assignment statement is an idiom that I have (perhaps naively) 
adopted. Is the .extend syntax more efficient? I can also see where it 
might be considered more readable or more accurate. (?)

Donnal Walter
Arkansas Children's Hospital

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