🐍 Python Pattern Challenge — Day 18

Pattern printing is a great way to improve your Python loops, spacing, repetition, and logical thinking. For Day 18, let's create a simple Star Hourglass Pattern ⭐.

This pattern starts with a wide row of stars, gradually becomes smaller toward the center, and then expands again. It is a good exercise for understanding increasing and decreasing loops.

Today's Challenge

Write a Python program to print:

Best and cleanest code will be rewarded! 🏆

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Solution 1 — Using Nested for Loops

n = 5

for i in range(n, 0, -1):
    print("  " * (n - i), end="")

    for j in range(2 * i - 1):
        print("*", end=" ")

    print()

for i in range(2, n + 1):
    print("  " * (n - i), end="")

    for j in range(2 * i - 1):
        print("*", end=" ")

    print()

How it works

The first loop creates the decreasing part:

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

The second loop creates the increasing part:

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

The expression:

2 * i - 1

controls the number of stars in each row.

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Solution 2 — Using String Multiplication

n = 5

for i in range(n, 0, -1):
    print("  " * (n - i) + "* " * (2 * i - 1))

for i in range(2, n + 1):
    print("  " * (n - i) + "* " * (2 * i - 1))
This version is shorter because Python can repeat a string using *.

For example:

"* " * 5
produces:

* * * * *

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Solution 3 — Using a Single Loop

n = 5

for i in list(range(n, 0, -1)) + list(range(2, n + 1)):
    print("  " * (n - i) + "* " * (2 * i - 1))

How it works

The sequence:

5, 4, 3, 2, 1, 2, 3, 4, 5




controls the complete hourglass.

When the value decreases, the pattern shrinks.

When it increases again, the pattern expands.

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⚡ Short & Clean Code

for i in [5, 4, 3, 2, 1, 2, 3, 4, 5]:
    print("  " * (5-i) + "* " * (2*i-1))

🔥 A single loop is enough to create the complete pattern.

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🚀 Challenge Yourself

Can you modify this pattern:

• Take n from the user using input()?
• Create the same pattern using a while loop?
• Make the hourglass larger?
• Replace * with another symbol?
• Create a hollow hourglass?
• Generate the sequence without manually writing [5, 4, 3, ...]?

Drop your solution below! 👇

18 Days. 18 Patterns. Stronger Python Logic. 🐍🔥

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