Part of the series

Several example codes

~2 min read • Updated Oct 6, 2025

Program Overview

This Python program reads an integer n between 1 and 80 and prints a square pattern of size n × n using asterisks (*).
The output highlights three specific parts of the square:
- The top row
- The last column
- The main diagonal (from top-left to bottom-right)


Python Code:


# Read n from user
n = int(input("Enter a number between 1 and 80: "))

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

Sample Output for n = 7:


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

Step-by-Step Explanation:

- The user inputs a number n
- The program checks that n is within the valid range
- A nested loop prints each row and column
- A star is printed if the position is on the top row (i == 0), last column (j == n - 1), or main diagonal (i == j)
- Otherwise, spaces are printed to maintain alignment


Written & researched by Dr. Shahin Siami