shell

Table of Content

• Name
• Status
• Synopsis
• Description
• Methods
  • shell.command
• Author
• Copyright and License

Name

shell

Status

The library is considered production ready.

Synopsis

Used to manage command. Set different arguments to execute different functions.

# set your commands in your source file: `demo.py`

from pykit import shell

arguments = {
    'echo_repr': (
                lambda x: sys.stdout.write(repr(x)),
                ('x', {'nargs': '+', 'help': 'just an input message'}),
            ),

    'foo': {
        'bar': lambda: sys.stdout.write('bar'),

        'bob': {
            'plus': (
                   lambda x, y: sys.stdout.write(str(x + y)),
                   ('x', {'type': int, help: 'an int is needed'}),
                   ('y', {'type': int, help: 'an int is needed'}),
                ),
        },
    },

    '__add_help__': {
        ('echo_repr',)           : 'output what is input.',
        ('foo', 'bar',)          : 'print a "bar".',
        ('foo', 'bob', 'plus',)  : 'do addition operation with 2 numbers.',
    },

    '__description__': 'this is an example command.',
}

shell.command(**arguments)

then you can execute your command as:

python demo.py echo_repr hello!
# 'hello!'

python demo.py foo bar
# 'bar'

python demo.py foo bob plus 1 2
# 3

and you can get a usage help message like:

$ python demo.py -h
---------------------------
usage: demo.py [-h] {echo_repr, foo bar, foo bob plus} ...

this is an example command.

positional arguments:
  {echo_repr, foo bar, foo bob plus} commands to select ...
    echo_repr            output what is input.
    foo bar              print a "bar".
    foo bob plus         do addition operation with 2 numbers.

optional arguments:
    -h, --help           show this help message and exit


$ python demo.py foo bob plus -h
--------------------------
usage: demo.py foo bob plus [-h] x y

positional arguments:
    x   an int is need
    y   an int is need

optional arguments:
    -h, --help           show this help message and exit

Description

A python module to manage commands.

Methods

shell.command

syntax: shell.command(**kwargs)

arguments:

• kwargs: A dict whose key is a str, used as a command, and value is a callable module, or another dict that has the same construction with kwargs.

  There are 2 optional reserved fields:

  • __add_help__: A dict whose key is a tuple of commands path to the callable module in kwargs, and value is a string message. Set this key to add help messages for every callable value in kwargs. Then you can use -h option to get help message when running.

    If this key is setted, then you can add parameter help messages for every callable value like: ('x', {'nargs': 1, 'type'=int, help='an int is needed'}), to make callable value as:

    (lamda x: do some thing with x,
      ('x', {'nargs': 1, 'type'=int, help='an int is needed'},
       ...
    )
    

    parameter help message is a dict and has the same format with key words arguments of argparser.paser.add_argument.

  • __description__: Set this key to describe what kwargs can use to do.

Author

Wenbo Li(李文博) [email protected]

Copyright and License

The MIT License (MIT)

Copyright (c) 2017 Wenbo Li(李文博) [email protected]