a, b = 2, 3
(a ** b) # = 8
pow(a, b) # = 8
import math
math.pow(a, b) # = 8.0 (always float; does not allow complex results)
import operator
operator.pow(a, b) # = 8Another difference between the built-in pow and math.pow is that the built-in pow can accept three arguments:
a, b, c = 2, 3, 2
pow(2, 3, 2) # 0, calculates (2 ** 3) % 2, but as per Python docs,
# does so more efficientlyThe function math.sqrt(x) calculates the square root of x.
import math
import cmath
c = 4
math.sqrt(c) # = 2.0 (always float; does not allow complex results)
cmath.sqrt(c) # = (2+0j) (always complex)To compute other roots, such as a cube root, raise the number to the reciprocal of the degree of the root. This could be done with any of the exponential functions or operator.
import math
x = 8
math.pow(x, 1/3) # evaluates to 2.0
x**(1/3) # evaluates to 2.0The function math.exp(x) computes e ** x.
math.exp(0) # 1.0
math.exp(1) # 2.718281828459045 (e)The function math.expm1(x) computes e ** x - 1. When x is small, this gives significantly better precision than math.exp(x) - 1.
math.expm1(0) # 0.0
math.exp(1e-6) - 1 # 1.0000004999621837e-06
math.expm1(1e-6) # 1.0000005000001665e-06
# exact result # 1.000000500000166666708333341666...