New submission from Matthew Brett:
The behavior of dict iteration has changed in Python 3.6, in that inserting
keys during iteration has a different and unpredictable affect. For this code:
d = {'foo': 1}
for key in d:
print(key)
d.pop(key)
d[key] = 1
Python 3.5 prints a single 'foo' (one pass through the loop). Python 3.6
generates five lines of 'foo' (five passes through the loop). Of course this
code is pathological, but I found this behavior from a bug in code where the
pathology was a lot less obvious - see https://github.com/nipy/nipy/issues/420
----------
messages: 286794
nosy: matthew.brett
priority: normal
severity: normal
status: open
title: Python 3.6 change in dict iteration when inserting keys
type: behavior
versions: Python 3.6
_______________________________________
Python tracker <[email protected]>
<http://bugs.python.org/issue29420>
_______________________________________
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
