How do I do exponentiation in python?

Question

def cube(number):
  return number^3
print cube(2)

I would expect cube(2) = 8, but instead I'm getting cube(2) = 1

What am I doing wrong?

Solution 1

^ is the xor operator.

** is exponentiation.

2**3 = 8

Solution 2

You can also use the math library. For example:

import math
x = math.pow(2,3) # x = 2 to the power of 3

Solution 3

if you want to repeat it multiple times - you should consider using numpy:

import numpy as np

def cube(number):
    # can be also called with a list
    return np.power(number, 3)

print(cube(2))
print(cube([2, 8]))

Comments

[Teepeemm]

There is also the builtin pow and math.pow.

[Jeru Luke]

the essence of being numpythonic

[Krishnadas PC]

Can you explain how it works when there are fractions like 2 ** 4.5?

[ShadowRanger]

@Teepeemm: Mind you, math.pow is basically 100% useless; ** does the job without an import, and doesn't force conversion to float. And the built-in pow is the only one accepting three arguments to efficiently perform modular exponentiation. I can't think of a single time I've ever wanted to perform exponentiation that implicitly converted my integer inputs to floating point (the only time math.pow is even remotely useful, and float(x) ** y would achieve that anyway).