Windows: add xonsh to the right click context menu

xonsh_context_menu.py

# Registers xonsh to the context menu (right click) on folders for Windows.

# Run following command line from WITHIN xonsh:
#
# $ exec(__import__('urllib.request').request.urlopen(r'https://gist.githubusercontent.com/nedsociety/91041691d0ac18bc8fd9e937ad21b055/raw/xonsh_context_menu.py').read());xonsh_register_right_click()
#
# To uninstall, run following command line from WITHIN xonsh:
#
# $ exec(__import__('urllib.request').request.urlopen(r'https://gist.githubusercontent.com/nedsociety/91041691d0ac18bc8fd9e937ad21b055/raw/xonsh_context_menu.py').read());xonsh_unregister_right_click()
#
# Q. Why do we need to run it inside xonsh?
# A. If xonsh is running on virtualenv then we need to point it in registry. This is trivial to detect from within (via sys.executable).

import winreg
import sys

def xonsh_register_right_click():
    def ensure_registry_key(root, k):
        elements = k.split('\\')
        for i in range(1, len(elements)):
            key_to_check = '\\'.join(elements[:i])
            with winreg.CreateKey(root, key_to_check):
                pass
    
    def create_registry_key_and_set_default_value(root, k, v):
        ensure_registry_key(root, k)
        with winreg.CreateKey(root, k) as hkey:
            winreg.SetValueEx(hkey, '', None, winreg.REG_SZ, v)
            
    cmdline = r"""
        "%s" -c "(lambda path=__import__('sys').path: path.remove('') if '' in path else None)(); __import__('os').chdir(r'%%V'); __import__('xonsh.main').main.main()"
    """.strip() % sys.executable
    
    # For right-clicking background
    create_registry_key_and_set_default_value(winreg.HKEY_CURRENT_USER, r'Software\Classes\Directory\Background\shell\xonsh', r'Open &xonsh window here')
    create_registry_key_and_set_default_value(winreg.HKEY_CURRENT_USER, r'Software\Classes\Directory\Background\shell\xonsh\command', cmdline)

    # For right-clicking folder
    create_registry_key_and_set_default_value(winreg.HKEY_CURRENT_USER, r'Software\Classes\Directory\shell\xonsh', r'Open &xonsh window here')
    create_registry_key_and_set_default_value(winreg.HKEY_CURRENT_USER, r'Software\Classes\Directory\shell\xonsh\command', cmdline)

def xonsh_unregister_right_click():
    def try_delete_registry_key(root, k):
        try:
            winreg.DeleteKey(root, k)
        except FileNotFoundError:
            pass
    try_delete_registry_key(winreg.HKEY_CURRENT_USER, r'Software\Classes\Directory\shell\xonsh\command')
    try_delete_registry_key(winreg.HKEY_CURRENT_USER, r'Software\Classes\Directory\shell\xonsh')
    try_delete_registry_key(winreg.HKEY_CURRENT_USER, r'Software\Classes\Directory\Background\shell\xonsh\command')
    try_delete_registry_key(winreg.HKEY_CURRENT_USER, r'Software\Classes\Directory\Background\shell\xonsh')