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This article is about finding factorial of any number in Python. In mathematics, a factorial is a positive number and represented as **n!. **A factorial is a product of all positive integers less than or equal to **n**.

For example, if we calculate the factorial of 3, then the product of all integers less than 6 will be **3*2*1 = 6**. It means the factorial of 3 is 6.

Now, let's implements it using the Python program.

**Step 1:** Take a number

**Step 2:** Check whether the number is greater than 1

**Step 3:** Iterate a loop for all the values less than the number

**Step 4:** Calculate factorial

**Step 5:** Repeat step 3 and 4 until the loop exits

**Step 6:** Display factorial

This algorithm is to calculate the factorial without using math.factorial() method. You can see its implementation in example2 below.

Python provides a math module that contains the **factorial()** method. We can use this method to calculate factorial for any number as we did in the below code example.

```
import math
# Take a number
num = 5
print(num)
fact = 1
# Find factorial
fact = math.factorial(num)
# Display result
print("Factorial is: ",fact)
```

**Output:**

5

Factorial is: 120

In this example, we are using for loop to calculate the factorial of a number. We can use this code if don't want to use math.factorial() method. See the code and output.

```
# Take a number
num = 5
print(num)
fact = 1
# Find factorial
if num >= 1:
for i in range (1, num+1):
fact = fact * i
# Display result
print("Factorial is: ",fact)
```

**Output:**

5

Factorial is: 120

Recursion is a technique in which a function calls itself until the base condition. Here, we used the recursion approach to find a factorial of a number in Python. See the code and output.

```
# Take a number
num = 5
print(num)
fact = 1
# Find factorial
def factorial(num):
if num < 2:
return 1
else:
return num * factorial(num-1)
# Display result
print("Factorial is: ",factorial(num))
```

**Output:**

5

Factorial is: 120