I'm trying to write a command line tool for Python that I can run like this..

```
orgtoanki 'b' 'aj.org' --delimiter="~" --fields="front,back"

```

Here's the script:

```
#!/usr/bin/env python3
import sys
import argparse

from orgtoanki.api import create_package

parser = argparse.ArgumentParser()
parser.add_argument('--fields', '-f', help="fields, separated by commas", type=str, default='front,back')
parser.add_argument('--delimiter', '-d', help="delimiter", type= str, default='*')
args = parser.parse_args()
name=sys.argv[1]
org_src=sys.argv[2]

create_package(name, org_src, args.fields, agrs.delimiter)

```

When I run it, I get the following error:

```
usage: orgtoanki [-h] [--fields FIELDS] [--delimiter DELIMITER]
orgtoanki: error: unrecognized arguments: b aj.org

```

Why aren't 'b' and 'ab.org' being interpreted as `sys.argv[1]` and `sys.argv[2]`, respectively?

And will the default work as I expect it to, if fields and delimiter aren't supplied to the command line?