Python Dictionary to find mirror characters in a string

Given a string and a number N, we need to mirror the characters from the N-th position to the end of the string in alphabetical order. In a mirror operation:

• 'a' becomes 'z'
• 'b' becomes 'y'
• 'c' becomes 'x', and so on.

Examples: 

Input: N = 3, word = paradox Output: paizwlc

Explanation: We mirror characters from position 3 to end.

We can solve this problem in Python using the Dictionary data structure. Below are the steps:

• The mirror value of 'a' is 'z', 'b' is 'y', etc.
• Create a dictionary mapping each character to its mirror value.
• Traverse characters from position N to the end of the string and replace them using the dictionary.
• Concatenate the unchanged prefix (first N-1 characters) with the mirrored part.

Implementation:

def mirrorChars(input,k):

    original = 'abcdefghijklmnopqrstuvwxyz'
    reverse = 'zyxwvutsrqponmlkjihgfedcba'
    dictChars = dict(zip(original,reverse))

    prefix = input[0:k-1]
    suffix = input[k-1:]
    mirror = ''

    for i in range(0,len(suffix)):
         mirror = mirror + dictChars[suffix[i]]
    print (prefix+mirror)
         
if __name__ == "__main__":
    input = 'paradox'
    k = 3
    mirrorChars(input,k)

paizwlc

Explanation:

• dict(zip(original, reverse)): creates a dictionary mapping each letter to its mirror.
• prefix = input[0:k-1]: first k-1 characters, unchanged.
• suffix = input[k-1:]: characters from position k onward, to be mirrored.
• input[0:k-1]: first k-1 characters, unchanged.
• input[k-1:]: characters from position k onward, to be mirrored.

Related Articles:

• Python - Mirror Image of String
• Python Dictionary Exercise