Table of contents  
Introduction  
Understanding Factorials  
Calculating Factorial Using a Loop  
Calculating Factorial Using Recursion  
Sample Problems and Solutions 
When working with numbers, it's often necessary to calculate the factorial of a given integer. The factorial of a number is the product of all positive integers less than or equal to that number. In this article, we'll explore how to find the factorial of a number using Python. We'll provide simple code examples and explanations to help beginners understand the concept of factorials and implement them in their programs.
To understand factorials better, let's consider an example. The factorial of 5, denoted as 5!, is calculated as follows:
5! = 5 × 4 × 3 × 2 × 1 = 120
Factorials are widely used in mathematics, statistics, and computer science. They can be used to solve a variety of problems, such as permutations, combinations, and probability calculations.
One way to calculate the factorial of a number is by using a loop. Here's a simple code snippet that demonstrates this approach:
def factorial(n):
result = 1
for i in range(1, n + 1):
result *= i
return result
number = 5
factorial_result = factorial(number)
print(f"The factorial of {number} is: {factorial_result}")
Code Explanation:
Output:
The factorial of 5 is: 120
Another approach to finding the factorial is by using recursion. In recursion, a function calls itself until it reaches a base case. Here's an example of how to calculate factorial using recursion in Python:
def factorial(n):
if n == 0:
return 1
else:
return n * factorial(n  1)
number = 5
factorial_result = factorial(number)
print(f"The factorial of {number} is: {factorial_result}")
Code Explanation:
Output:
The factorial of 5 is: 120
Now that we understand how to calculate factorials, let's solve a few sample problems using Python.
Problem 1: Calculate the factorial of a given number 'n'.
def factorial(n):
result = 1
for i in range(1, n + 1):
result *= i
return result
number = 6
factorial_result = factorial(number)
print(f"The factorial of {number} is: {factorial_result}")
Output:
The factorial of 6 is: 720
Problem 2: Calculate the factorial of the first 'n' natural numbers and display the results.
def factorial(n):
result = 1
for i in range(1, n + 1):
result *= i
return result
n = 5
for i in range(1, n + 1):
factorial_result = factorial(i)
print(f"The factorial of {i} is: {factorial_result}")
Output:
In this article, we explored how to calculate the factorial of a number using Python. We covered two methods: one using a loop and another using recursion. Factorials are essential in various mathematical and computational problems. By understanding the concept and implementing the code examples provided, you should now be able to calculate factorials in Python. Keep practicing and exploring different applications of factorials to strengthen your understanding of this important concept in mathematics and programming.
49 videos38 docs18 tests

49 videos38 docs18 tests


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