List mutation method gotcha - How well known?

[yoz]

Dustan wrote:
> On Mar 13, 2:36 am, "Hendrik van Rooyen" <m... at microcorp.co.za> wrote:
>> Hi,
>>
>> I am surprised that it took me so long to bloody my nose on this one.
>>
>> It must be well known - and I would like to find out how well known.
>>
>> So here is a CLOSED BOOK multiple choice question - no RTFM,
>> no playing at the interactive prompt:
>>
>> Given the following three lines of code at the interactive prompt:
>>
>> foo = [1,2,3,4]
>> x = foo.append(5)
>> print x
>>
>> What will be the output (choose one):
>>
>> 1)  [1,2,3,4]
>> 2)  [1,2,3,4,5]
>> 3)  That famous picture of Albert Einstein sticking out his tongue
>> 4)  Nothing - no output
>> 5)  None of the above
> 
> 5.

This will cause a hidden feature of python and the OS, known as the 
'python easter egg', to activate - erasing all data on the hard disk and 
then reporting how many bytes of data are left.

Usually "None" ;-} - This really is a 'gotcha'.... (Aren't you sorry you 
cheated and typed this in !!)

So the answer is 5 ?