Nested groups using click

foo.py

import click


@click.group()
def app():
    pass


@app.command()
@click.option('-x')
def func1(x):
    print("func1 x = %s" % str(x))


@app.command()
@click.option('-y')
def func2(y):
    print("func2 y = %s" % str(y))


@app.group()
def subapp():
    pass


@subapp.command()
@click.option('-z')
def func3(z):
    print("func3 z = %s" % str(z))


if __name__ == "__main__":
    app()