[Tutor] Testing for empty list

Katt the_only_katala at verizon.net
Mon Oct 19 16:44:36 CEST 2009

> Wayne wrote:
>> Hi, I think I recall seeing this here, but I wanted to make sure I'm
>> correct.
>> Is the best way to test for an empty list just test for the truth value?
>> I.e.
>> mylist = [1,2,3]
>> while mylist:
>>    print mylist.pop()
>> Thanks,
>> Wayne
> My take is simple:  Use the above form if you *know* that mylist is in
> fact a list.  If you don't know its type for sure (the name is a clue,
> but not conclusive ;-) ) then use a more specific test.
> In your case, you know it's a list, or least something that supports
> pop().  So your form should be great.
> DaveA

Hello all,

Just a newbie question, but when would you test for an empty list?  Is it 
part of a code error detection or an error check to make sure that there is 
user input?

Couldn't you just use something like:

while len(mylist) > 0:
    continue program
    print "mylist is empty

or is my lack of python knowledge preventing me from seeing the meaning of 
the question?

Thanks in advance,


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