pylibcli

A few libraries intend to help writing cli program more convenient.

Installation

Via pip:

$ pip install libcli

Usage

Basic

Hello world: examples/hello_world.py:

from libcli import default, run

@default
def main():
    print("Hello world!")

if __name__ == '__main__':
    run()

Define default and command

libcli.command or libcli.command(**kwargs) could be used as a decorator to define a command function.

Keyword arguments not starting with '_' passed to libcli.command would be used as a hint to the option of the decorated function with the same name.

Keyword _name can be used to override the command name, otherwie the function name would be used.

libcli.default or libcli.default(**kwargs) is quite similar to command.

default function could only be defined once.

If defined, default function is always call at the very beginning.

Define error

libcli.command or libcli.command(**kwargs) could be used to decorate an exception.

libcli.command(**kwargs) could be used to define an errno other than default 127.

libcli.run would catch all defined errors, and exit with errno as exit code.

Define option type

by docstring: examples/simple_options.py:

@default
def main(*args, aflag=None, bflag=None, cvalue=None):
    """Parse the args.

    :param aflag: Set aflag
    :type aflag: flag.
    :param bflag: Set bflag
    :type bflag: flag.
    :param int cvalue: Set cvalue
    """

by decorator hint: examples/simple_options_hinted.py:

@default(aflag='_a', bflag='_b', cvalue='c:int,float')
def main(*args, aflag=None, bflag=None, cvalue):

otherwise guess from option default value.

Hint string: [_]shortopt[:[[[type1],type2],type3...] | ::[[[type1],type2],type3...]=default]

• startswith a '_' the option would be used as short option only, otherwise the option name would be used as a long option
• shortopt should be a list of characters to be used as short option
• without colons means this option requires no argument, if set function would be called with this option set a value not None.
• a single colon means this option requires an argument
• double colon measn the argument is optional, a default value is required
• type list has priority

Possible types (not case sensitive):

• str a command argument could always be parsed as a string
• int, hex, dec, oct, bin parse argument as an integer, int accepts 0x, 0o, 0b, 0(c-style octal literal), default decimal
• float parse as a floating point number
• flag, none accept no argument, if set value will be not None, currently ''

following types may vary in future:

• bool '0', 'n', 'no', 'f', 'false', 'nil', 'nul', 'null', 'none', '-' is False, otherwise True
• list a comma separated list, currently all values are supposed to be string
• dict a comma separated key=value pair list, key and value are supposed to be string

Chained commands

If a command function returns a not None object, it would be used as the first argument of the next command function call.

Thus with a factory method as default, member functions returning self as command would do the trick.

examples/crud_class.py

examples/simple_arithmetic.py

Submodules

opttools

Specify command with decorators. Automatically generate option list from decorator hinting, docstring and option default value. Parse a list of argumens and call corresponding method in a chainable style.

getopt

Yet another implementation to work close to GNU getopt. Unlike standard library, pylibcli.getopt employs an iterator interface. Optional argument supported. opttools use getopt internally.