On Fri, 7 Jul 2017 05:29 pm, Dan Wissme wrote: > Strange behavior in Python 3.6.0 > >>> i = 3000 > >>> j = 3000 > >>> i is j > False > >>> n = 4000 ; m = 4000 ; n is m > True
The Python interpreter is allowed to cache integers and reuse them. The interactive interpreter sometimes does so: if you write the same int literal on the same line in the interactive interpreter, it may re-use the same object instead of creating two equal objects. You should **NEVER** use `is` when you want to check for equality. You cannot rely on Python to cache or not cache int values. Whatever it does is purely an implementation detail that is subject to change without notice. -- Steve “Cheer up,” they said, “things could be worse.” So I cheered up, and sure enough, things got worse. -- https://mail.python.org/mailman/listinfo/python-list
