Convert a normal string into a zig_zag format

zig_zag_conversion.py

## Convert a normal string into a zig-zag form

import numpy as np

class Solution:
    def convert(self, string:str, numRows:int) -> tuple:
        if numRows < 1:
            return string
        numCol = round(len(string)/numRows)+1
        if numCol < 1:
            return string
        stacks = [[] for i in range(0, numCol)]
        #additional = []
        additionalCount = numRows-2
        w = 0

        for i in range(len(stacks)):
            stacks[i].extend(string[w:w+numRows])
            w += numRows
            if len(stacks[i]) == numRows:
                """for those characters which will form the zig-zag structure
                or say, diagonal structure"""
                try:
                    temp = additionalCount
                    while temp > 0:
                        stacks[i][temp] = list(stacks[i][temp]) # add those char. with their partner character
                        stacks[i][temp].append(string[w])
                        temp -= 1
                        w += 1
                except:
                    pass
            else:
                # Fill None if there's nothing to add & len of that stack is less than numRow
                stacks[i].extend([None]*(numRows - len(stacks[i])))
        
        print(stacks)
        def zigzagToString(stacks: list, n: int) -> str:
            """ build a zigzag string """
            new_string = ""
            # convert a list into matrix
            stacks = np.array(stacks)

            for i in range(n):
                for j in stacks[:, i]:
                    if j is None:
                        pass
                    elif type(j) == list:
                        new_string += ''.join(j)
                    else:
                        new_string += j

            return new_string
        
        return zigzagToString(stacks, numRows)


if __name__ == "__main__":
    s = Solution()
    while True:
        string = str(input(" Enter string : "))
        numRows = int(input(" Enter Rows : "))
        print(s.convert(string, numRows))