openstack
/
deb-python-oslo.serialization
Code Issues Proposed changes

Use {} instead of dict() 

There is a performance impact when using dict() instead of {}
in CPython (up to 6 times longer).
Considering the to_primitive function is recursive this can
have quite an effect.

Measuring:
$ python2.7 -m timeit -n 1000000 -r 5 -v 'dict()'
raw times: 0.24 0.24 0.24 0.239 0.24
1000000 loops, best of 5: 0.239 usec per loop

$ python2.7 -m timeit -n 1000000 -r 5 -v '{}'
raw times: 0.0417 0.0413 0.0407 0.0411 0.042
1000000 loops, best of 5: 0.0407 usec per loop

For more information:
https://doughellmann.com/blog/2012/11/12/
the-performance-impact-of-using-dict-instead-of-in-cpython-2-7-2/

Change-Id: Ia0b5892773a19cbabe40313a3bc788580a943f53
This commit is contained in:
Edan David 2016-06-21 10:18:28 -04:00
parent 23866b6d6c
commit 1ec85e90cd
1 changed files with 2 additions and 2 deletions
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4
oslo_serialization/jsonutils.py
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@ -143,8 +143,8 @@ def to_primitive(value, convert_instances=False, convert_datetime=True,
level=level,
max_depth=max_depth)
if isinstance(value, dict):
return dict((recursive(k), recursive(v))
for k, v in six.iteritems(value))
return {recursive(k): recursive(v)
for k, v in six.iteritems(value)}
elif hasattr(value, 'iteritems'):
return recursive(dict(value.iteritems()), level=level + 1)
# Python 3 does not have iteritems