# Python program to display half diamond pattern of numbers with star border

• Difficulty Level : Medium
• Last Updated : 02 Feb, 2021

Given a number n, the task is to write a Python program to print a half diamond pattern of numbers with a star border.

Examples:

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```Input: n = 5
Output:

*
*1*
*121*
*12321*
*1234321*
*123454321*
*1234321*
*12321*
*121*
*1*
*

Input: n = 3
Output:

*
*1*
*121*
*12321*
*121*
*1*
*```

Approach:

• Two for loops will be run in this program in order to print the numbers as well as stars.
• First print * and then run for loop from 1 to (n+1) to print up to the rows in ascending order.
• In this particular for loop * will be printed up to i and then one more for loop will run from 1 to i+1 in order to print the numbers in ascending order.
• Now one more loop will run from i-1 to 0 in order to print the number in the reverse order.
• Now one star will be printed and this for loop will end.
• Now second for loop will run from n-1 to 0 to print the pattern as in the middle in which the numbers are in a reverse manner.
• In this for loop also the same work will be done as in first for loop.
• The required pattern will be displayed.

Below is the implementation of the above pattern:

## Python3

 `# function to display the pattern up to n``def` `display(n):  ``   ` `    ``print``(``"*"``)``     ` `    ``for` `i ``in` `range``(``1``, n``+``1``):``        ``print``(``"*"``, end``=``"")``         ` `        ``# for loop to display number up to i``        ``for` `j ``in` `range``(``1``, i``+``1``):  ``            ``print``(j, end``=``"")`` ` `        ``# for loop to display number in reverse direction    ``        ``for` `j ``in` `range``(i``-``1``, ``0``, ``-``1``):  ``            ``print``(j, end``=``"")`` ` `        ``print``(``"*"``, end``=``"")``        ``print``()`` ` `    ``# for loop to display i in reverse direction``    ``for` `i ``in` `range``(n``-``1``, ``0``, ``-``1``):``        ``print``(``"*"``, end``=``"")``        ``for` `j ``in` `range``(``1``, i``+``1``):``            ``print``(j, end``=``"")`` ` `        ``for` `j ``in` `range``(i``-``1``, ``0``, ``-``1``):``            ``print``(j, end``=``"")`` ` `        ``print``(``"*"``, end``=``"")``        ``print``()`` ` `    ``print``(``"*"``)`` ` ` ` `# driver code``n ``=` `5``print``(``'\nFor n ='``, n)``display(n)`` ` `n ``=` `3``print``(``'\nFor n ='``, n)``display(n)`

Output:

```For n = 5
*
*1*
*121*
*12321*
*1234321*
*123454321*
*1234321*
*12321*
*121*
*1*
*

For n = 3
*
*1*
*121*
*12321*
*121*
*1*
*```

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