https://www.python.org/dev/peps/pep-0238/{Describing the old python-2 behavior:}-------- Quote: -------The classic division operator makes it hard to write numerical expressions that are supposed to give correct results from arbitrary numerical inputs. For all other operators, one can write down a formula such as xy*2 + z, and the calculated result will be close to the mathematical result (within the limits of numerical accuracy, of course) for any numerical input type (int, long, float, or complex). But division poses a problem: if the expressions for both arguments happen to have an integral type, it implements floor division rather than true division.-----------------------To guarantee the correct mathematical behavior in python2, one would probably have to write:`````` def true_math_div(a,b) : if type(a) is int or type(a) is long : a = float(a) if type(b) is int or type(b) is long : b = float(b) return a/b `````` as a and b could be int, float, complex, or some object defining the method __div__.