Python calls CMD to copy file code sharing

import os
def load() :
    filename = os.getcwd() + r'fromto.txt'
    if os.path.isfile(filename) :        
        f = open(filename)
        try :
            lines = f.readlines()
        finally :
            f.close()
            return lines
    else :
        print(' Please create a fromto.txt.')
        input()
        exit()
def display(_lines) :
    linenum = 1
    s = ' The serial number   The source file   The target file n'
    for line in _lines :
        s += str(linenum) + ' ' + line
        linenum += 1
    return s + 'n' + r' Please enter the serial number :'
def work(s, _lines) :
    cmd = r'copy /y ' + _lines[int(s)-1]
    print(cmd)
    os.system(cmd)
if __name__ == "__main__" :

    lines = load()
    while True :
        try :
            s = input(display(lines)).strip()
            if s.lower() == 'exit' :
                break
            if int(s) == 0 :
                lines = load()
                print(' reloaded ')
                continue
            work(s, lines)

        except :
            input('--Error--')

The format of fromto.txt is that the left side of each line is the source file and the right side is the target file (or target directory).
Anyway is actually the packaging copy once.

Fromto. TXT content

d:txt1.txt d:txt2.txt
d:txt*.txt d:txt2