Part of the series

Several example codes

~2 min read • Updated Oct 5, 2025

Program Overview

This Python program reads an integer n between 6 and 80 and prints a square pattern of size n × n using asterisks (*).
The output shows only the four borders and the main diagonal (from top-left to bottom-right).


Python Code:


# Read n from user
n = int(input("Enter a number between 6 and 80: "))

# Validate input
if 6 <= n <= 80:
    for i in range(n):
        row = ''
        for j in range(n):
            if i == 0 or i == n - 1 or j == 0 or j == n - 1 or i == j:
                row += '* '
            else:
                row += '  '
        print(row)
else:
    print("The number must be between 6 and 80.")

Sample Output for n = 5:


* * * * *  
* *       *  
*   *     *  
*     *   *  
* * * * *

Step-by-Step Explanation:

- The user inputs a number n
- The program checks that n is between 6 and 80
- A nested loop prints each row and column
- A star is printed if the position is on the border or the main diagonal (i == j)
- Otherwise, spaces are printed to keep the square aligned


Written & researched by Dr. Shahin Siami