Python Program to Print Star Pattern in X Shape

Introduction

An X-shaped star pattern is a symmetrical arrangement of stars (*) in the shape of the letter 'X'. The stars are printed diagonally from the top-left to the bottom-right and from the top-right to the bottom-left. This exercise is great for practicing nested loops and conditional logic in Python.

Problem Statement

Create a Python program that:

• Accepts the size of the pattern (an odd number).
• Prints a star (*) pattern in the shape of an 'X'.

Example:

• Input: size = 5
• Output:

  *   *
   * *
    *
   * *
  *   *
  

Solution Steps

1. Input the Size: The user specifies the size of the X pattern, which should be an odd number to ensure symmetry.
2. Use Nested Loops: The outer loop handles the rows, and the inner loop handles printing the stars and spaces.
3. Conditionally Print Stars: Print stars on the diagonals (positions where the row and column indices match or add up to size - 1).

Python Program

# Step 1: Input the size of the pattern (must be odd)
size = int(input("Enter the size of the X pattern (odd number): "))

# Step 2: Outer loop for rows
for i in range(size):
    # Step 3: Inner loop for columns
    for j in range(size):
        # Step 4: Print stars at diagonal positions
        if i == j or i + j == size - 1:
            print("*", end="")
        else:
            print(" ", end="")
    # Move to the next line after printing each row
    print()

Explanation

Step 1: Input the Size of the Pattern

• The program starts by asking the user for the size of the X pattern. The size must be an odd number to create symmetry.

Step 2: Outer Loop for Rows

• The outer loop controls how many rows are printed. It runs from 0 to size - 1.

Step 3: Inner Loop for Columns

• The inner loop controls how many columns are printed in each row.

Step 4: Conditional Printing of Stars and Spaces

• Stars (*) are printed at the diagonal positions:
  • On the main diagonal (i == j),
  • On the anti-diagonal (i + j == size - 1).
• Spaces are printed elsewhere to form the X shape.

Output Example

For size = 5, the output will be:

*   *
 * *
  *
 * *
*   *

For size = 7, the output will be:

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

Conclusion

This Python program prints a star pattern in the shape of an X using nested loops and conditional logic. Stars are printed on the diagonals, while spaces are printed elsewhere to create the X shape. This exercise helps in practicing loop control, conditional statements, and formatting output in Python.