Convert text-based tables to CSV - specifically for tables generated by https://www.tablesgenerator.com/text_tables/ - does not support multiline or vertically merged cells

table_to_csv.py

import csv
import re
import os
import sys


def table_to_csv(args):
    if len(args) < 3:
        outpath = os.path.join(
            os.path.dirname(os.path.abspath(args[1])),
            os.path.splitext(args[1])[0] + ".csv",
        )
    else:
        outpath = os.path.abspath(args[2])

    if os.path.isfile(outpath):
        print(outpath, "already exists")
        confirm = input("Overwrite? Y/N ")
        if confirm.lower() != "y":
            exit(1)

    with open(args[1], encoding="utf-8", errors="ignore") as file:
        tablelines_raw = file.readlines()

    table_positions_dict = dict()
    table_list_cleaned = []

    for index, line in enumerate(tablelines_raw):
        line = line.rstrip()

        if re.match(r"^\+[-=]{2,}.+\+$", line):
            table_positions_dict[index] = [
                pos for pos, char in enumerate(line) if char == "+"
            ]
        elif re.match(r"^[╔╠╒╞├][─═]{2,}", line):
            table_positions_dict[index] = [
                pos
                for pos, char in enumerate(line)
                if re.match(r"[╔╦╗╠╬╣╒╤╕╞╪╡├┼┤]", char)
            ]

        if (index % 2) != 0:
            try:
                splitpoints = table_positions_dict[index - 1][:-1]
                line = line[:-1] + " "

                raw_splits = [
                    line[i:j] for i, j in zip(splitpoints, splitpoints[1:] + [None])
                ]
                splits_cleaned = [x[1:].strip() for x in raw_splits]

                table_list_cleaned.append(splits_cleaned)
            except KeyError:
                print("Error: input file does not have expected table structure")
                exit(1)

    with open(outpath, "w", newline="", encoding="utf-8") as f:
        writer = csv.writer(f, dialect="excel")
        writer.writerows(table_list_cleaned)


if len(sys.argv) < 2:
    print("Error: not enough arguments")
    print("Usage: table_to_csv.py input.txt [output.csv]")
    exit(1)

table_to_csv(sys.argv)