.cod to .dec file converter

Cockatrice to XMage.py

from os import remove
from uuid import uuid4

def get_xml_tag(line):
    tag = line = line.strip(' ').strip('<')
    tag = tag.split(' ')[0]
    if '>' in tag:
        tag = tag.split('>')[0]
    return tag

def open_cod(filename):
    deckname = ''
    current_board = 'main'  
    
    main_board_ct = list()
    main_board_names = list()
    
    side_board_ct = list()
    side_board_names = list()
    
    main_board = dict()
    side_board = dict()

    with open(filename) as text:
        for line in text:
            tag = get_xml_tag(line)
            if tag == 'deckname':
                #fix this later
                deckname = line.split(">")
                deckname = deckname[1]
                deckname = deckname.split("<")
                deckname = deckname[0]
            elif tag == 'zone' and 'main' in line:
                current_board = 'main'
            elif tag == 'zone' and 'side' in line:
                current_board = 'side'
                line = line.split('=')
            elif tag == 'card':
                line = line.strip(' ')
                line_parts = line.split('number="')
                number = line_parts[1].split('"')[0]
                line_parts = line.split('name="')
                name = line_parts[1].split('"')[0]
                if current_board == 'main':
                    main_board_ct.append(number)
                    main_board_names.append(name)
                else:
                    side_board_ct.append(number)
                    side_board_names.append(name)

    main_board = zip(main_board_ct, main_board_names)
    side_board = zip(side_board_ct, side_board_names)
        
    return deckname, main_board, side_board
    
def write_dec(deckname, main_board, side_board):
    out = ''

    if not deckname:
        deckname = 'Untitled_Deck_' + uuid4().hex
    
    for ct, name in main_board:
        out += ct + ' ' + name  + '\n'      
    for ct, name in side_board:
        out += 'SB: ' + ct + ' ' + name + '\n'
        
    f = open(deckname + '.dec', 'w')
    f.write(out)
    f.close()
    
    
def main():
    cod_name = input('Please enter the name of the file to convert (include .cod extension): ')
    while cod_name.split('.')[-1] != 'cod':
        cod_name = input('Incorrect filetype. Please enter the name of a .cod file: ')
    
    deckname, main_board, side_board = open_cod(cod_name)
    write_dec(deckname, main_board, side_board)
    
main()

How do i use it to covert files