Need more info on functions

Question

Please someone help on describing step by step:

def power(x,y):
if y==0:
return 1
else:
return x * power(x, y-1)

print(power(2,3))

Output is: 8

Answer 1

power takes the first argument as the number, while the second argument as the power. so this is what is happening behind the scenes
2 * power(2, 3-1)
2 * power(2,2)
2* 4
8

Answer 2

ghali Thank you my friend for your kind help. actually I heard about built-in function <pow(x,y)> but here, power is not defined to be as (x**y)!! that’s why it’s not clear to me.

Answer 3

ghali lawal how do you count (2 * power (2,2))?!
how power(2,2) will be 4?!

Answer 4

Jay Matthews how do u simplify (return x * power(x, y-1))
for example if we have (2,3), the result would be:

return 2 * power(2, 3-1)

then, we have

return 2 * power(2,2).

how do you get the result of (power 2,2) to be multiplied by x(which is 2)!?

Answer 5

Dolan power(2,2) is 4, lemme evaluate:
power(2,2) = 2 ** 2 = 4
power(3,2) = 3 ** 2 = 9
in short, you are squaring the number on the left

Answer 6

Dolan, power doesnt need to be defined, it is a built in function, so when whenever you call it, it automatically does power(x**y), hope you get it

Answer 7

Jay Matthews , Untill here is quite clear, but here we don’t have the built-in fiction <pow(x,y)> and x ** y is not defined to the (power) function. it is (power) not (pow). that’s why it is not clear.

Answer 8

ghali lawal , Thank you.