On 06/09/2010 8.34, Roelof Wobben wrote:
Hello,
I have this programm:
...
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 []
I would add a line like:
return seq
at the end of the make_empty function.
Can anyone explain why that happens ?
I think Python doesn't know what exactly is the value you need to
receive from the make_empty function. That's why I'd make it clear.
Otherwise, you know what happens...
I quote the following from
http://diveintopython.org/getting_to_know_python/declaring_functions.html
"In fact, every Python function returns a value; if the function ever
executes a return statement, it will return that value, otherwise it
will return None, the Python null value."
Roelof
Francesco
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