Generate a .bat file to use for invoking a Python script

create_bat_wrapper.bat

@echo off
cls
if %1. == . goto error
if not %2. == . goto error

python "%~dp0/create_bat_wrapper.py" %1
goto exit

:error
echo Drop exactly one file onto my icon.

:exit
echo;
pause > nul | set /p =Press any key to exit...

create_bat_wrapper.py

import sys
import os

# A batch file can have at most nine arguments.
numwords = [
    'zero', 'one', 'two', 'three', 'four',
    'five', 'six', 'seven', 'eight', 'nine']

py_name = sys.argv[1]
root, ext = os.path.splitext(py_name)
if ext not in {'.py', '.pyw'}:
    sys.exit("Input file doesn't look a Python script; aborting.")
bat_name = root + '.bat'

while True:
    try:
        args = int(input('How many arguments? '))
        if args in range(10):
            break
    except ValueError:
        pass
    print('> Must be an integer between 0 and 9.')

path_spec = None
while path_spec not in {'a', 'abs', 'absolute', 'r', 'rel', 'relative'}:
    path_spec = input('Absolute or relative script directory? ').lower()

script_name = {
    'a': py_name,
    'r': os.path.join('%~dp0', os.path.basename(py_name))
}[path_spec[0]]
print(f'> Script will be specified as: "{script_name}"')

with open(bat_name, 'w') as f:
    f.write('@echo off\ncls\n')
    for i in range(args):
        f.write(f"if %{i + 1}. == . goto error\n")  # argument cannot be empty
    f.write(f"if not %{args + 1}. == . goto error\n")  # cannot pass extra arguments
    f.write(f'\npython "{script_name}"')
    for i in range(args):
        f.write(f" %{i + 1}")
    f.write('\ngoto exit\n')
    f.write(f"\n:error\necho Drop exactly {numwords[args]} ")
    f.write(('file' if args == 1 else 'files') + ' onto my icon.\n')
    f.write('\n:exit\necho;\npause > nul | set /p =Press any key to exit...\n')

print('Done.')