Python Program to Compute the Power of a Number

Example 1: Calculate power of a number using a while loop

base = 3
exponent = 4

result = 1

while exponent != 0:
    result *= base
    exponent-=1

print("Answer = " + str(result))

Output

Answer = 81

In this program, base and exponent are assigned values 3 and 4 respectively.

Using the while loop, we keep on multiplying the result by base until the exponent becomes zero.

In this case, we multiply result by base 4 times in total, so result = 1 * 3 * 3 * 3 * 3 = 81.

Example 2: Calculate power of a number using a for loop

base = 3
exponent = 4

result = 1

for exponent in range(exponent, 0, -1):
    result *= base

print("Answer = " + str(result))

Output

Answer = 81

Here, instead of using a while loop, we've used a for loop.

After each iteration, the exponent is decremented by 1, and the result is multiplied by the base exponent number of times.

Both programs above do not work if you have a negative exponent. For that, you need to use the pow() function in the Python library.

Also Read: Python range()

Example 3: Calculate the power of a number using pow() function

base = 3
exponent = -4

result = pow(base, exponent)

print("Answer = " + str(result))

Output

Answer = 0.012345679012345678

pow() accepts two arguments: base and exponent. In the above example, 3 raised to the power -4 is calculated using pow().

Also Read:

• Python Program to Display Powers of 2 Using Anonymous Function