Python Program to Compute the Power of a Number

Power:

A power is an expression that describes repeated multiplication of the same factor.

Examples:

Example1:

Positive Exponent:

Input:

base = 7 power = 4

Output:

The result is 2401

Example2:

Negative Exponent:

Input:

base = 7 power = -2

Output:

The result is 0.02040816326530612

This article will teach you how to compute the power of a number.

Calculate the Power of a Number

Below are the ways to calculate the power of a number :

Using While loop
Using For loop
Using pow() function
Using ** operator in Python

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Method #1:Using While loop

Scan the base and power values.
Create a variable resultValue and initialize it with 1.
Using the while loop, we continue to multiply the resultValue by the base until the exponent reaches zero.
Print the resultValue.

Below is the implementation:

# given base value and power value
baseValue = 7
powerValue = 4
# initialize the result value to 1
resultValue = 1
# Loop till power becomes 0
while powerValue != 0:
    resultValue = resultValue * baseValue
    powerValue = powerValue-1

print("The result is", resultValue)

Output:

The result is 2401

Method #2: Using For loop

Instead of a while loop, we’ve used a for loop here.
Scan the base and power values.
Create a variable resultValue and initialize it with 1.
The exponent is decremented by one for each iteration, and the resultValue is multiplied by the base exponent a number of times.
Print the resultValue.

Below is the implementation:

# given base value and power value
baseValue = 7
powerValue = 4
# initialize the result value to 1
resultValue = 1
# Loop till power becomes 0 using for loop
for i in range(powerValue):
    resultValue = resultValue*baseValue
    # decrement the powerValue
    powerValue = powerValue-1

print("The result is", resultValue)

Output:

The result is 2401

Note:

If you have a negative exponent, none of the above methods will function.
You must use the pow() function from the Python library to accomplish this.

Method #3:Using pow() function

We can calculate the power value using pow() function.

It works for negative exponent too.

1)Calculating the power of positive exponent

Below is the implementation:

# given base value and power value
baseValue = 7
powerValue = 4
# calculating the power of base
resultValue = pow(baseValue, powerValue)
# print the result
print("The result is", resultValue)

Output:

The result is 2401

2)Calculating the power of negative exponent

Below is the implementation:

# given base value and power value
baseValue = 7
powerValue = -2
# calculating the power of base
resultValue = pow(baseValue, powerValue)
# print the result
print("The result is", resultValue)

Output:

The result is 0.02040816326530612

Method #4:Using ** operator in Python

We can calculate the power value using ** .

It works for negative exponent too.

1)Calculating the power of positive exponent

Below is the implementation:

# given base value and power value
baseValue = 7
powerValue = 4
# calculating the power of base
resultValue = baseValue**powerValue
# print the result
print("The result is", resultValue)

Output:

The result is 2401

2)Calculating the power of negative exponent

Below is the implementation:

# given base value and power value
baseValue = 7
powerValue = -2
# calculating the power of base
resultValue = baseValue**powerValue
# print the result
print("The result is", resultValue)

Output:

The result is 0.02040816326530612

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