Find Power of a Number in Python

In this article, we will show you how to find the power of a number in python. Below are the various methods to accomplish this task ?

• Using for loop

• Using Recursion

• Using pow() function

• Using ** operator

Using for loop

Algorithm (Steps)

Following are the Algorithm/steps to be followed to perform the desired task -.

• Create a function findPower() that returns the power of a Number. The function accepts number, and exponent value as parameters.

• Take a variable that stores the result and initialize its value with 1.

• To obtain the power, multiply the given number by the result exponent. We use the below loop to multiply the exponent number of times

• Use the for loop, to traverse in the range 1 to given exponent+1.

• Inside the loop, Multiply the result by the given number

• Use the return keyword to return the resultant power.

• Create 2 separate variables for storing input number and exponent values.

• Call the above-defined findPower() function by passing the input number, and exponent values as arguments to it and print the returned result of function.

• In the same way, calculating for other numbers

Example

The following program returns the power of a number using the for loop-

# creating a function that returns the power of a Number
# It accepts Number, and exponent values as parameters
def findPower(number, exponent):
   # intializing a variable with 1 (it stores the resultant power)
   resultPower =1
   # traversing in the range from 1 to given exponent+1
   for i in range(1, exponent+1):
      # Multiplying the result with the given number
      resultPower=resultPower*number
   # returning the resultant power
   return resultPower
# input number, exponent values
number = 5
exponent = 3
# calling the findPower() function by passing the number,exponent values
# as arguments
print("Value of",number,"raised to the power",exponent,"(",number,"^",exponent,") =", findPower(number,exponent))
#, In the same way, calculating for other numbers
number = 4
exponent = 0
print("Value of",number,"raised to the power",exponent,"(",number,"^",exponent,") =", findPower(number,exponent))

Output

On executing, the above program will generate the following output ?

Value of 5 raised to the power 3 ( 5 ^ 3 ) = 125
Value of 4 raised to the power 0 ( 4 ^ 0 ) = 1

Using Recursion

Algorithm (Steps)

Following are the Algorithm/steps to be followed to perform the desired task -.

• Create a function findPower() that returns the power of a Number. The function accepts number, power/exponent value as parameters

• Use the if conditional statement, to check whether the exponent value passed is equal to 0.

• Return 1 if the condition is true i,e, exponent value is 0.

• Subtract the exponent value by 1 and return the resultant power using recursive logic.

• Call the above-defined findPower() function by passing the input number, and exponent values as arguments to it and print the returned result of function.

Example

The following program returns the power of a number using the recursive logic -

# creating a function that returns the power of a Number
# It accepts Number, power/exponent value as parameters
def findPower(number, exponent):
   # checking whether the exponent value passed is equal to 0
   if exponent == 0:
   # returning 1 if the condition is true
      return 1
   # Subtract the exponent value by 1 and return the resultant power using recursive logic
      return number * findPower(number, exponent-1)
# input number, exponent values
number = 5
exponent = 3
# calling the findPower() function by passing the number, exponent values
# as arguments
print("Value of",number,"raised to the power",exponent,"(",number,"^",exponent,") =", findPower(number,exponent))

Output

On executing, the above program will generate the following output ?

Value of 5 raised to the power 3 ( 5 ^ 3 ) = 125

Using pow() function

In Python, the pow() function calculates the power of any positive integer.

It returns the value of x to the power of y (x^y).

Syntax

pow(x,y)

Parameters

• x - It is the numerical value (base value)

• y - It is the power of numerical value (exponent value)

Algorithm (Steps)

Following are the Algorithm/steps to be followed to perform the desired task -.

• Create a variable to store the input number.

• Create another variable to store the exponent/power value.

• Use the pow() function to print the resultant power of a number i.e, inputNumber ^ inputPower by passing the number, and exponent values as arguments to it and print the resultant power.

Example

The following program returns the power of a number using the pow() function -

# input number
inputNumber = 5
# input exponent value
inputPower = 3
# printing the resultant power value using the pow() function
print("Value of 5 raised to the power 3(5^3)=", pow(inputNumber, inputPower))

Output

On executing, the above program will generate the following output ?

Value of 5 raised to the power 3(5^3)= 125

Using ** operator

The exponential operator(**) can be used to calculate the power of a number.

Since importing a module or calling a function is not necessary, this is the most convenient to use.

Algorithm (Steps)

Following are the Algorithm/steps to be followed to perform the desired task -.

• Create a variable to store the input number.

• Create a variable to store the exponent/power value.

• Use the exponential operator(**) to print the resultant power of a number i.e, inputNumber ^ inputPower.

Example

The following program returns the power of a number using the ** operator -

# input number
inputNumber = 6
# input exponent value
inputPower = 2
# printing the resultant power of a number using exponential operator(**)
print("Value of 6 raised to the power 2(6^2)=", inputNumber**inputPower)

Output

On executing, the above program will generate the following output -

Value of 6 raised to the power 2(6^2)= 36

Conclusion

In this article, we learned four different Python methods for calculating the power of a given number and exponent. We also learned how to calculate power without the use of built-in functions.