My main python functions accepts argv and calls two other functions with these arguments to set up the whole application.
The issue is that if argv includes -h (`--help) then it is passed to the first function, it prints it's usage message (generated by argparse) as expected, like below:
optional arguments:
-h, --help show this help message and exit
-x section
but then execution is stopped!, and we are back at the prompt.
I would like the execution to continue so the second function is also called, and its usage message also gets printed. Does anyone know how this can be achieved?
You need to catch the SystemExit exception:
exited = None
try:
function1(argv)
except SystemExit as e:
# don't exit just yet
exited = e
function2(argv)
# If function 2 *did not* exit, there was a legitimate reason
# re-raise the SystemExit exception
if exited is not None:
raise exited
Note that I store the system exit exception raised in function1; it could be that it was raised as a result of a different action, not the -h flag. If function2 doesn't raise an exception itself, we re-raise the original SystemExit exception to clean up properly.
The except SystemExit as e: statement captures the exception in a local variable e. The local variable thus assigned is normally deleted at the end of the except block (to prevent a reference cycle); if you want to use that exception outside of the except suite you need to store it in a new variable; this is why exited is a separate variable defined outside of the except suite.
Alternatively, you can opt to remove the -h switch from the function1 argparser altogether by using the add_help=False option, then handling help manually there.