# 1. Introduction

The hollow pyramid pattern is an interesting variation of the standard pyramid pattern that introduces the concept of controlling output within nested loops. In this pattern, stars (*) are printed only on the borders of the pyramid, leaving the interior hollow. This Python tutorial will guide you through creating a hollow pyramid pattern, emphasizing conditional statements within loops.

# 2. Program Steps

1. Ask the user for the number of rows in the pyramid.

2. Use nested loops to iterate over each row and column, printing stars (*) on the border and spaces inside.

3. Apply conditional logic to determine whether to print a star or a space.

# 3. Code Program

``````# User input for the number of rows
rows = int(input("Enter the number of rows: "))

# Outer loop for each row
for i in range(1, rows + 1):
# Inner loop for each column
for j in range(1, 2 * rows):
# Print stars for the first row, last row, first column, and last column
if i == rows or i + j == rows + 1 or j - i == rows - 1:
print("*", end="")
else:
print(" ", end="")
print()
``````

### Output:

```Enter the number of rows: 5
*
* *
*   *
*     *
*********
```

### Explanation:

1. The program begins by asking the user to enter the desired number of rows for the pyramid. This value is stored in the variable rows.

2. A for loop then iterates over each row of the pyramid, from 1 to rows inclusive.

3. Within this loop, another for loop iterates over each column. The range is from 1 to 2 * rows to ensure the pyramid is properly centered and hollow.

4. Conditional statements within the inner loop determine where to print stars. Stars are printed for:

- The last row (i == rows) to create the base of the pyramid.

- The left and right borders of the pyramid (i + j == rows + 1 or j - i == rows - 1).

5. Spaces are printed in all other positions to create the hollow effect inside the pyramid.

6. The end="" parameter in the print function ensures that the stars and spaces for a single row are printed on the same line.

7. After completing the inner loop for a row, a call to print() without arguments moves the cursor to the next line, ready to print the next row of the pyramid.