Message167861
This is not a bug. extend is a procedure with a side effect: the "self" object (i.e. "a" in your example) is modified.
By convention, procedures return None in Python, as opposed to functions, which have no side effect but return a result. This is to avoid code like
def combine(a, b):
return a.extend(b)
a = ...
b = ...
c = combine(a,b)
If extend would return the "self" list, then people may think that they get a fresh, new list, and then wonder why a is modified.
IOW: your bug report is actually invalid; the result that print shows is exactly the right result that extend returns. |
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Date |
User |
Action |
Args |
2012-08-10 08:58:14 | loewis | set | recipients:
+ loewis, laki |
2012-08-10 08:58:14 | loewis | set | messageid: <1344589094.3.0.980341755863.issue15614@psf.upfronthosting.co.za> |
2012-08-10 08:58:13 | loewis | link | issue15614 messages |
2012-08-10 08:58:13 | loewis | create | |
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