Quick program to find a string inside a grid of letters as if it were a standard word search where words can only go to the right or downward

puzzle.txt

DGOODDODGOODDO
ODOOGGGDODGOGG
OGOGDOODGOODDD
DGDOOOGGOOGDGO
OGDGOGDGOGGOGD
DDDGDDODOOGDOO
ODGOGGDOOGGOOD

wordsearcher

#!/usr/bin/python3

import sys, re
import numpy as np


def main():
    # command line options
    filename = sys.argv[1] # filename of the grid to search
    search = sys.argv[2] # string to find

    f = open(filename)
    lines = f.readlines()
    #left-right
    for row in range(len(lines)):
        line = lines[row]
        result = re.search(search, line)
        if result is not None:
            print("Found at row " + str(row + 1) + ", column " + str(result.start() + 1) + " east")
            return
        rline = line[::-1]
        result = re.search(search, rline)
        if result is not None:
            print("Found at row " + str(row + 1) + ", column " + str(result.start() + 1) + " west")
            return
    #up-down
    for col in range(len(lines[0])):
        column = ''.join([line[col] for line in lines])
        result = re.search(search, column)
        if result is not None:
            print("Found at column " + str(col + 1) + ", row " + str(result.start() + 1) + " south")
            return
        rcolumn = column[::-1]
        result = re.search(search, rcolumn)
        if result is not None:
            print("Found at column " + str(col + 1) + ", row " + str(result.start() + 1) + " north")
            return
    #diagonals...using numpy because its easiest
    matrix = np.array([list(l.strip()) for l in lines])
    diags = [matrix[::-1,:].diagonal(i) for i in range(-matrix.shape[0]+1,matrix.shape[1])]
    diags.extend(matrix.diagonal(i) for i in range(matrix.shape[1]-1,-matrix.shape[0],-1))
    diagonals = [''.join(list(n)) for n in diags]

    for i in range(len(diagonals)):
        line = diagonals[i]
        result = re.search(search, line)
        if result is not None:
            print("Found in diagonal '" + line + "' (index " + str(i) + " of " + str(len(diagonals)) + ")")
            return
        rline = line[::-1]
        result = re.search(search, rline)
        if result is not None:
            print("Found in diagonal '" + line + "' (reversed) (index " + str(i) + " of " + str(len(diagonals)) + ")")
            return

if __name__ == "__main__":
    main()