Comparison of power to multiplication in python

Question

Read somewhere in my adventure in optimizing my mandelbrot program that if you are for example squaring something. Using the mandelbrot equation as the example that z * z is faster than z**2. Is this true, and if it is why is this so? Is it due to the fact that z**2 still computes trivial cases such as 0?

Answer 1

I am one of the people who have suggested the optimization and yes, it is true. In the example below, squaring with * is over 3 times as fast as with **2.

from timeit import repeat
print(repeat('z*z', 'z=.54321 + .56789j'))
print(repeat('z**2', 'z=.54321 + .56789j'))
# prints
[0.07780417092306088, 0.05484807785182001, 0.05577646621573226]
[0.2081317598277747, 0.19060335713839965, 0.1913974058615736]

Since both operations give the same answer

>>> z*z
(-0.02742194800000003+0.6169670537999999j)
>>> z**2
(-0.02742194800000003+0.6169670537999999j)

the second must eventually do the first (plus whatever else it does.