Argcomplete provides easy, extensible command line tab completion of
arguments for your Python script.

It makes two assumptions:

* You're using bash as your shell
* You're using argparse to manage your command line arguments/options

Argcomplete is particularly useful if your program has lots of
options or subparsers, and if your program can dynamically suggest
completions for your argument/option values (for example, if the user
is browsing resources over the network).