On Mon, Sep 6, 2010 at 8:34 AM, Roelof Wobben <rwob...@hotmail.com> wrote:
> Hello,
>
> I have this programm:
>
> def encapsulate(val, seq):
> if type(seq) == type(""):
> return str(val)
> if type(seq) == type([]):
> return [val]
> return (val,)
>
> def insert_in_middle(val, seq):
> middle = len(seq)/2
> return seq[:middle] + encapsulate(val, seq) + seq[middle:]
>
> def make_empty(seq):
> """
> >>> make_empty([1, 2, 3, 4])
> []
> >>> make_empty(('a', 'b', 'c'))
> ()
> >>> make_empty("No, not me!")
> ''
> """
> word2=""
> teller=0
> if type(seq) == type([]):
> teller=0
> while teller < len(seq):
> seq[teller]=""
> teller = teller + 1
> elif type(seq) == type(()):
> tup2 = list (seq)
> while teller > tup2.len():
> tup2[teller]=""
> teller = teller + 1
> seq = tuple(tup2)
> else:
> seq = ""
>
> test = make_empty([1, 2, 3, 4])
> print test
>
> But now I get None as output instead of []
>
> Can anyone explain why that happens ?
test = make_empty([1, 2, 3, 4]) makes test equal to the return value
of make_empty. But make_empty does not return anything, and in that
case its return value is made equal to empty. Compare:
def f(x):
x = x + 1
def g(x):
x = x + 1
return x
def h(x):
return x +1
print f(1)
>> None
print g(1)
>> 2
print h(1)
>> 2
--
André Engels, andreeng...@gmail.com
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