Is cube root integer?

Question

This seems to be simple but I cannot find a way to do it. I need to show whether the cube root of an integer is integer or not. I used is_integer() float method

Answer 1

In SymPy there is also the integer_nthroot function which will quickly find the integer nth root of a number and tell you whether it was exact, too:

>>> integer_nthroot(primorial(12)+1,3)
(19505, False)

So your function could be

def is_perfect_cube(x): return integer_nthroot(x, 3)[1]

(And because SymPy is open source, you can look at the routine to see how integer_nthroot works.)