Python: get command to open file from windows registry

file_command.py

# coding: utf-8
import os
import winreg
import sys


def read_extension_regkey(extension):
    path = r"Software\Classes\{}\OpenWithProgIDs".format(extension)
    print("read_extension_regkey path={}".format(path))
    try:
        registry_key = winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, path, 0, winreg.KEY_READ)
        subkeys = []
        i = 0
        while True:
            try:
                subk = winreg.EnumValue(registry_key, i)
                print("read_extension_regkey subkey={}".format(subk[0]))
                subkeys.append(subk[0])
            except:
                break
            i += 1
        winreg.CloseKey(registry_key)
        return subkeys
    except WindowsError as err:
        print("read_extension_regkey {}".format(err), file=sys.stderr)
        return []


def read_programtype_regkey(program_type):
    path = r"Software\Classes\{}\shell\Open\command".format(program_type)
    print("read_programtype_regkey path={}".format(path))
    try:
        registry_key = winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, path, 0, winreg.KEY_READ)
        value = winreg.QueryValueEx(registry_key, '')
        winreg.CloseKey(registry_key)
        return value
    except WindowsError as err:
        print("read_programtype_regkey {}".format(err), file=sys.stderr)
        return None


def get_programs_for_extension(extension):
    print("get_programs_for_extension extension={}".format(extension))
    programs = []
    for prg in read_extension_regkey(extension):
        program = read_programtype_regkey(prg)
        if program is not None:
            print("get_programs_fror_extension program: {}".format(program))
            programs.append(program)

    return programs


if __name__ == "__main__":
    filenames = ["my document.odt", "image.jpg"]
    for filename in filenames:
        _, extension = os.path.splitext(filename)
        print(get_programs_for_extension(extension))