What is the rationale for gcd(x, y) in Fractions returning a negative value when y is negtive?
For example gcd(3, -7) returns -1, which means that a co-prime test that would work in many other languages 'if gcd(x, y) == 1' will fail in Python for negative y. And, of course, since -|x| is less than |x|, returning -|x| rather than |x| is not returning the greatest common divisor of x and y when y is negative. -- https://mail.python.org/mailman/listinfo/python-list
