python - Call function based on argparse

Question

I'm new to python and currently playing with it. I have a script which does some API Calls to an appliance. I would like to extend the functionality and call different functions based on the arguments given when calling the script.

Currently I have the following:

parser = argparse.ArgumentParser()
parser.add_argument("--showtop20", help="list top 20 by app",
                    action="store_true")
parser.add_argument("--listapps", help="list all available apps",
                    action="store_true")
args = parser.parse_args()

I also have a

def showtop20():
    .....

and

def listapps():
....

How can I call the function (and only this) based on the argument given? I don't want to run

if args.showtop20:
   #code here

if args.listapps:
   #code here

as I want to move the different functions to a module later on keeping the main executable file clean and tidy.

Answer 1

Since it seems like you want to run one, and only one, function depending on the arguments given, I would suggest you use a mandatory positional argument ./prog command, instead of optional arguments (./prog --command1 or ./prog --command2).

so, something like this should do it:

FUNCTION_MAP = {'top20' : my_top20_func,
                'listapps' : my_listapps_func }

parser.add_argument('command', choices=FUNCTION_MAP.keys())

args = parser.parse_args()

func = FUNCTION_MAP[args.command]
func()