[New-bugs-announce] [issue6637] non-empty defaultdict .copy() fails returning empty dict

Tom Clarke report at bugs.python.org
Mon Aug 3 23:25:52 CEST 2009

New submission from Tom Clarke <t.clarke at ic.ac.uk>:

The enclosed script when run under 2.6.2 IDLE standard distribution on
x86 shows that shallow copy (.copy()) of a non-empty defaultdict object
returns an empty defaultdict!

Other ways to copy, e.g. defaultdict(none, d.items()), work fine.

Bug appears under:
Python 2.6.2 (r262:71605, Apr 14 2009, 22:40:02) [MSC v.1500 32 bit
(Intel)] on win32

I have tested it on two different computers. They both also have the
visual installed from a v2.6 binary - but I can't see why this would
change standard libraries.

Hope I am not being stupid - this seems to big a bug to be real!

**Documentation on defaultdict states (nearly all) methods are same as
dict, and on dict defines copy() as returning a shallow copy.

**replace defaultdict by dict and this example works as expected

Best wishes, Tom

PS - I am new to python so forgive any stupidity!

components: Library (Lib)
messages: 91242
nosy: tomcl
severity: normal
status: open
title: non-empty defaultdict .copy()  fails returning empty dict
type: behavior
versions: Python 2.6

Python tracker <report at bugs.python.org>

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