On 07/02/13 17:32, wesley chun wrote:
On Thu, Feb 7, 2013 at 12:09 AM, Sunil Tech<sunil.tech...@gmail.com> wrote:
If a method has no return type?
what will it return?
note the original question is partially invalid... Python functions and
methods aren't typed. however, i imagine the OP really meant *return value*
instead, so the answer is really the following:
functions *and* methods with no explicit return *value* return None... this
happens when you either have no return statement or just return by itself
with no object given.
one exception is __init__()... you're never supposed to return anything
from it... ever. i can't think of any others... can you?
In-place modification methods typically return None. Functions and methods
intended to operate as procedures, or via side-effect, also typically
return None:
list.sort
list.reverse
list.append
list.extend
dict.clear
dict.update
set.clear
set.update
__delitem__
__setitem__
_delattr__
__setattr__
random.shuffle
file.close
print # Python 3 only
But as far as I know, __init__ is the only one which actually enforces the
rule that it returns None, at least in Python 3.3.
--
Steven
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