How to conditionally make python argparse a module requires additional arguments
The main purpose:
my_framework create Project_title /path/to/project
OR
my_framework create Project_title
(i.e. use the current working directory)
OR
my_framework update
(i.e. update my_framework rather than create a new project)
I know I can make it name
optional by giving it a default, but it's actually name
not required if the user entered create
as the first argument.
The best solution I have come up with is to use the default for name
and then if the argument name
is equal to its default, throw an error. But if there is a way to do argparse, make this work for me, I'd rather learn it.
Write two scripts my_framework_create
, and my_framework_update
no appeal to me aesthetically.
#!/usr/bin/env python
import argparse
import os
import shutil
from subprocess import call
template_path = "/usr/local/klibs/template"
parser = argparse.ArgumentParser("MY_FRAMEWORK CLI", description='Creates a new MY_FRAMEWORK project or updates MY_FRAMEWORK')
parser.add_argument('action', choices=['create', 'update'], type=str, help='<help text>')
parser.add_argument('name', type=str, help='<help text>')
parser.add_argument('path', default=os.getcwd(), nargs="?", type=str, help='<help text>')
args = parser.parse_args()
if args.action == "create":
# do the create stuff
if args.action == "update":
# do the update stuff
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The best way to do this is subparser
Example from docs:
>>> parser = argparse.ArgumentParser()
>>> subparsers = parser.add_subparsers(title='subcommands',
... description='valid subcommands',
... help='additional help')
>>> subparsers.add_parser('foo')
>>> subparsers.add_parser('bar')
>>> parser.parse_args(['-h'])
usage: [-h] {foo,bar} ...
optional arguments:
-h, --help show this help message and exit
subcommands:
valid subcommands
{foo,bar} additional help
In your case, you have create
both update
as separate sub-parameters.
Example:
def create(args):
# do the create stuff
print(args)
def update(args):
# do the update stuff
print(args)
parser = argparse.ArgumentParser()
subparsers = parser.add_subparsers(title='subcommands',
description='valid subcommands',
help='additional help')
create_parser = subparsers.add_parser('create')
create_parser.add_argument('name', type=str)
create_parser.set_defaults(func=create)
update_parser = subparsers.add_parser('update')
update_parser.set_defaults(func=update)
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