Alphabet Rangoli

 

You are given an integer, . Your task is to print an alphabet rangoli of size . (Rangoli is a form of Indian folk art based on creation of patterns.)
Different sizes of alphabet rangoli are shown below:
#size 3

----c----
--c-b-c--
c-b-a-b-c
--c-b-c--
----c----

#size 5

--------e--------
------e-d-e------
----e-d-c-d-e----
--e-d-c-b-c-d-e--
e-d-c-b-a-b-c-d-e
--e-d-c-b-c-d-e--
----e-d-c-d-e----
------e-d-e------
--------e--------

#size 10

------------------j------------------
----------------j-i-j----------------
--------------j-i-h-i-j--------------
------------j-i-h-g-h-i-j------------
----------j-i-h-g-f-g-h-i-j----------
--------j-i-h-g-f-e-f-g-h-i-j--------
------j-i-h-g-f-e-d-e-f-g-h-i-j------
----j-i-h-g-f-e-d-c-d-e-f-g-h-i-j----
--j-i-h-g-f-e-d-c-b-c-d-e-f-g-h-i-j--
j-i-h-g-f-e-d-c-b-a-b-c-d-e-f-g-h-i-j
--j-i-h-g-f-e-d-c-b-c-d-e-f-g-h-i-j--
----j-i-h-g-f-e-d-c-d-e-f-g-h-i-j----
------j-i-h-g-f-e-d-e-f-g-h-i-j------
--------j-i-h-g-f-e-f-g-h-i-j--------
----------j-i-h-g-f-g-h-i-j----------
------------j-i-h-g-h-i-j------------
--------------j-i-h-i-j--------------
----------------j-i-j----------------
------------------j------------------
The center of the rangoli has the first alphabet letter a, and the boundary has the  alphabet letter (in alphabetical order).
Function Description
Complete the rangoli function in the editor below.
rangoli has the following parameters:
int size: the size of the rangoli
Returns
string: a single string made up of each of the lines of the rangoli separated by a newline character (\n)
Input Format
Only one line of input containing , the size of the rangoli.
Constraints
Sample Input
5
Sample Output
--------e--------
------e-d-e------
----e-d-c-d-e----
--e-d-c-b-c-d-e--
e-d-c-b-a-b-c-d-e
--e-d-c-b-c-d-e--
----e-d-c-d-e----
------e-d-e------
--------e--------

Solution :-

import string
def print_rangoli(size):
    n = size                                   #---> input 
    l1 = list(map(chr,range(97,123)))             #---> convertig number to ascii value
    m=len('-'.join(l1[n-1::-1]+l1[1:n]))            #---> getting the length of the middle line 
    for i in range(1,n):                       #---> forward for loop 
        print('-'.join(l1[n-1:n-i:-1]+l1[n-i:n]).center(m,'-'))                          #---> printing the pattern 
    for i in range(n,0,-1):                                       #---> reverse for loop 
        print('-'.join(l1[n-1:n-i:-1]+l1[n-i:n]).center(m,'-'))                        #---> printing the pattern  
if __name__ == '__main__':
    size = int(input())
    print_rangoli(size)