Python Values Return and Recursion :

Function Return Values :

To let a function return a value, use the return statement :

Example :

  1. def my_function(x):
  2. return 5 * x
  4. print(my_function(2))
  5. print(my_function(4))
  6. print(my_function(6))
  7. print(my_function(8))
  9. print("\n python function return example :) ")
  11. input()

Output :

python function values return example

Recursion :

Python also accepts function recursion, which means a defined function can call itself. Recursion is a common mathematical and programming concept. It means that a function calls itself. This has the benefit of meaning that you can loop through data to reach a result.

The developer should be very careful with recursion as it can be quite easy to slip into writing a function which never terminates, or one that uses excess amounts of memory or processor power. However, when written correctly recursion can be a very efficient and mathematically-elegant approach to programming.

Example :

  1. #find factorial number using recursion function
  3. def my_function(n):
  4. if n == 1:
  5. return n
  6. else:
  7. return n*my_function(n-1)
  9. num = int(input("Enter a number: ")) # take input(int type) from the user
  11. if num < 0: # check is the number is negative
  12. print("Sorry, Factorial does not exist for negative numbers.")
  13. elif num == 0:
  14. print("The factorial of 0 is 1")
  15. else:
  16. print("The factorial of",num,"is",my_function(num))
  18. input()

Output :

python recursion function to find a factorial number

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