Execute function via arg

Question

What I would like to do is when I enter a specific argument it starts a function, is this possible through argparse. So if I hit the add argument in my application it triggers the "add" function.

parser = argparse.ArgumentParser(description='to do list')
parser.add_argument('-a', '--add', help='add an item to the todo list')
parser.add_argument('-r', '--remove',)
parser.add_argument('-l', '--list',)
args = parser.parse_args()

def add(args):
    conn = sqlite3.connect('todo.db')
    c = conn.cursor()
    c.execute("INSERT INTO todo VALUES (args.add, timestamp)")

Answer 1

Sure, you can just use add as the type parameter:

def add(args):
    conn = sqlite3.connect('todo.db')
    c = conn.cursor()
    c.execute("INSERT INTO todo VALUES (args, timestamp)")

parser.add_argument('-a', '--add', type=add)

If that's not good enough, you can subclass argparse.Action and pretty much get argparse to do whatever you want whenever it encounters an argument.