I got this from the fractions module:
if type(a) is int is type(b):
And as far as I can tell this does the same as:
if type(a) == int == type(b):
But I don't really get how those "chained" is really work, or what's their use when (imo) == looks more readable. Here's the full function
def gcd(a, b):
    """Calculate the Greatest Common Divisor of a and b.
    Unless b==0, the result will have the same sign as b (so that when
    b is divided by it, the result comes out positive).
    """
    import warnings
    warnings.warn('fractions.gcd() is deprecated. Use math.gcd() instead.',
                  DeprecationWarning, 2)
    if type(a) is int is type(b):
        if (b or a) < 0:
            return -math.gcd(a, b)
        return math.gcd(a, b)
    return _gcd(a, b)
