'==' vs. 'is' behavior

Skip Montanaro skip at mojam.com
Fri Nov 12 10:56:40 EST 1999

    Andy> Further experimentation shows that this seems to work for integers
    Andy> through 99, but that starting with 100 the results of the 'is'
    Andy> test return 0, as I would expect.

Python's intobject.c file maintains a cache of the integer objects 0 through
99.  If you check the id() of small integers you'll see they are always
represented by the same object.

read-the-source-luke-ly y'rs,

Skip Montanaro | http://www.mojam.com/
skip at mojam.com | http://www.musi-cal.com/
847-971-7098   | Python: Programming the way Guido indented...

More information about the Python-list mailing list