sum() requires number, not simply add

Thu Feb 23 16:41:28 EST 2012

On 23 February 2012 21:23, Buck Golemon <buck at yelp.com> wrote:
> def sum(values,
> base=0):
>      values =
> iter(values)
>>      try:
>          result = values.next()
>      except StopIteration:
>          return base
>>      for value in values:
>          result += value
>      return result

This is definitely not backward compatible. To get something that has
a better chance of working with existing code, try this (untested):
_sentinel = object()
def sum(iterable, start=_sentinel):
 if start is _sentinel:
 iterable = iter(iterable)
 try:
 start = iterable.next()
 except StopIteration:
 return 0
 for x in iterable:
 start += x
 return start
del _sentinel
-- 
Arnaud

sum() requires number, not simply __add__

sum() requires number, not simply add