Surprise using the 'is' operator

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    Wesley> as a side note, the ints that are cached (for current versions
    Wesley> of Python) are in range(-1, 100)... is this documented
    Wesley> somewhere?

Other than the code, probably not.  Since it's an implementation
optimization, I see no particular reason that it should be documented
elsewhere.  Hmmm... It would be interesting if we had a buildbot which
through a series of slightly twisty C macros built an interpreter that
eliminates the free list altogether to make sure nothing depends on its
presence or size.

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