Embed ipython when using a cmd.Cmd (or kmd.Kmd) shell

ipy.py

from IPython.core.completer import IPCompleter
from IPython.config.loader import Config
import rl


def setup_ipython():
    try:
        get_ipython()
    except NameError:
        cfg = Config()
        prompt_config = cfg.PromptManager
        prompt_config.in_template = 'In <\\#>: '
        prompt_config.in2_template = '   .\\D.: '
        prompt_config.out_template = 'Out<\\#>: '
        banner = "** Dropping into IPython **"
        exit_msg = "** Exiting IPython **"

        from IPython.frontend.terminal.embed import InteractiveShellEmbed

        ipshell = InteractiveShellEmbed(config=cfg, banner1=banner, exit_msg=exit_msg)
        rl.readline.set_completer(IPCompleter(shell=ipshell).complete)
        rl.readline.parse_and_bind("tab: complete")
        return ipshell
        # Now ipshell() will open IPython anywhere in the code
    else:
        # Define a dummy ipshell() so the same code doesn't crash inside an
        # interactive IPython
        def ipshell():
            pass
        return ipshell

main.py

class BaseCmd(kmd.Kmd):
    # other stuff omitted...
    
    def do_ipy(self, arg):
        'Enter the development shell'

        """Run the ipython shell (developer only)"""
        ipshell = setup_ipython()
        ipshell('***Called from top level. '
                'Hit Ctrl-D to exit interpreter and continue program.\n'
                'Note that if you use %kill_embedded, you can fully deactivate\n'
                'This embedded instance so it will never turn on again')