homepage

The relevant piece of Python code from fractions.py looks like this:
 if type(numerator) is int is type(denominator):
 # *very* normal case
 g = math.gcd(numerator, denominator)
 if denominator < 0:
 g = -g
 else:
 g = _gcd(numerator, denominator)
I wonder whether we should simply drop the type check: math.gcd should accept anything that supports __index__ (and that includes NumPy integer types and anything that implements numbers.Integral).
OTOH, math.gcd will return a plain int, and if we have some subclass myint of int, we might want all the arithmetic to stay in the domain of myints (though I'm not really sure _why_ we'd want that). In that case we'll need to restore the pure Python _gcd implementation.