cltools 0.5.0

simple example :

Imagine, you’ve got a simple class that make tasks, and you want to make a command line tool with that. Let’s say, it’s a calculator module calclib.py:

#!/usr/bin/env python

class Calc(object) :
    def __init__(self) :
        pass
    def add(self, value1, value2) :
        return value1+value2
    def mult(self, value1, value2) :
        return value1*value2

Then, we will write a simple class and transform into a runnable tool:

#!/usr/bin/env python

import sys
from calclib import Calc
from cltools import CLRunner

@CLRunner.runnable()
class CalcTool(object) :
    '''A simple command-line wrapper for calclib'''
    def __init__(self) :
        self._calc = Calc()


    def get_two_params(self, args) :
        if len(args) != 2 :
            # errorexit provided by CLRunnable parent
            self.errorexit("Need two values VALUE1 and VALUE2 as arguments")
        try :
            value1 = int(args[0])
        except Exception :
            self.errorexit("Value [%s] should be a valid number" % (args[0],))
        try :
            value2 = int(args[1])
        except Exception :
            self.errorexit("Value [%s] should be a valid number" % (args[1],))
        return value1, value2

    @CLRunner.command()
    def add(self, args, kwargs) :
        '''Add two values VALUE1 and VALUE2 given as parameters'''
        value1, value2 = self.get_two_params(args)
        value = self._calc.add(value1, value2)
        self.status("Result : [%s]" % (value,))

    @CLRunner.command()
    def mult(self, args, kwargs) :
        '''Multiplie two values VALUE1 and VALUE2'''
        value1, value2 = self.get_two_params(args)
        value = self._calc.mult(value1, value2)
        self.status("Result : [%s]" % (value,))

    @CLRunner.command()
    def help(self, args=[], kwargs={}) :
        '''Get this help'''
        super().help()

if __name__ == '__main__' :
    calctool = CalcTool()
    if not(calctool.run( sys.argv )) :
        sys.exit(1)

Now we can test our command line tool:

$ ./calc.py
Usage: calc.py COMMAND_NAME [OPTION] [VALUES]
A simple command-line wrapper for calclib

Commands:
    add                  Add two values VALUE1 and VALUE2 given as parameters
    help                 Get this help
    mult                 Multiplie two values VALUE1 and VALUE2

Error : Need a command name

$ ./calc.py add 4 17
Result : [21]

$ ./calc.py add 15 66 33
Error : Need two values VALUE1 and VALUE2 as arguments

Note that the help is automatically generate based on commands declared in the class, and the online doc attached to the class and methods.