jsh-py3 0.1.0

Junos-like shell library for Python 3

jsh_py3 is a Junos-inspired CLI library for your Python apps. If you’ve ever logged into a Junos device, you’ll know how good the CLI is. It offers:

• tab-completion, including completion of names of items in the config

• help by pressing “?” at any point

• completion on pressing either space, tab or enter

jsh_py3 attempts to reproduce some of these features (and others) in a Python library based on Readline, to allow you to build better quality CLIs for your apps.

Installation

Install from PyPI using pip install jsh_py3.

Basic Usage

The library takes a CLI “layout”, which is a dictionary-based tree structure describing your CLI commands. For example, a completely useless CLI with just an exit command, you would define it like this:

import jsh_py3

layout = {
    'exit': jsh_py3.exit,
}

jsh_py3.run(layout)

jsh_py3.run is a shortcut for the following:

cli = jsh_py3.JSH(layout)

while True:
    try:
        cli.read_and_execute()
    except jsh_py3.JSHError as err:
        print err
    except EOFError:
        break

This creates a basic layout with a single available command (exit), passes it to an instance jsh_py3.JSH, and starts an infinite loop, using the read_and_execute method of the jsh_py3 CLI object to interact with the user. For more control over this loop, you should write your own instead of using jsh_py3.run.

This provides a CLI that looks like the following:

> ?
Possible completions:
  exit
> ex?
Possible completions:
  exit
> exit ?
Possible completions:
  <[Enter]>   Execute this command
> exit