cliq 0.9.3

a lightweight framework for creating command line interfaces quickly

cliq: creating command line interfaces quickly in Python

cliq is a lightweight framework for creating a command line application or writing a libary powered with command line tools in Python.

• supports nested subcommands
• equiped with init and config system
• supports multiple command line tools in a single library
• only depends on the standard library

Quick Start

Install cliq:

$ pip install cliq

Create your project:

$ cliq create project ./myapp
$ pip install -e ./myapp
$ myapp

Create a new command:

$ cliq create command do.py
$ python do.py -h

Add the command to your project:

$ mv do.py ./myapp/myapp/main/command/
$ myapp do -h

Remove help, init, config commands if you don't need them:

$ cd ./myapp/myapp/main/command
$ rm help.py init.py config.py

Commands

• A command is standalone and complete by itself if you don't need config.
• You can run it as an independent script.
• Just copy a command script into your project.
• There is nothing to be configured.

Try toy sample commands:

$ cliq create project myapp --sample
$ pip install -e ./myapp 
$ myapp say hello
hello
$ cliq please say hello
hello
$ cliq please sum 1 2 3 4 5
15.0

Write your command:

• It's just an argparse.ArgumentParser
• See https://docs.python.org/3/library/argparse.html
• Add arguments to the self.parser
• Write the run method
• Your command runs standalone if you don't use the app variable, which allows your command to access config variables through app.config.

Create a command script:

$ cliq create command say.py 

Edit the script:

...

class Command(SimpleCommand):
    def __init__(self, app = None, name = __name__):
        super().__init__(app, name)

        # self.parser is an argparse.ArumentParser
        # see https://docs.python.org/3/library/argparse.html       
        #
        # add arguments. for example:
        #
        # self.parser.add_argument('input', type=str, help='input filename')
        # self.parser.add_argument('-v', '--verbose', action='store_true', help='verbose')
        # self.parser.add_argument('-o', '--output', type=str, help='output filename')

    def run(self, argv):
        args = self.parser.parse_args(argv)

        # implement command line functionalities
        print(args)
 
...

Library

Create a project and add modules:

$ cliq create project mylib
$ pip install -e ./mylib
$ echo 'def mean(*x): return sum(x)/len(x)' > mylib/mylib/math.py

It is a normal library:

>>> import mylib.math
>>> mylib.math.mean(1, 2, 3, 4, 5)
3.0

Add commands. For example,

$ cliq create command mylib/mylib/main/command/mean.py

import sys
from cliq.main.command import SimpleCommand
import mylib.math

def init(app):
    return Command(app)

class Command(SimpleCommand):
    def __init__(self, app = None, name = __name__):
        super().__init__(app, name)

        self.parser.add_argument('x', type=float, nargs='+')

    def run(self, argv):
        args = self.parser.parse_args(argv)

        # implement command line functionalities
        print(mylib.math.mean(*args.x))
 

Run the command:

$ mylib mean 1 2 3 4
2.5

Tutorial

Concepts

app, command and subcommand

cliq supports nested command line interfaces to the depth 3: app, command, and subcommand.

$ cliq   create     project       ./myapp      --with-sample-commands
$ pip    install                               -e ./myapp
$ myapp  please     sum           1 2 3 
$ myapp  say                      hello
$ myapp                                        --help
  <app>  <command>  <subcommand>  <arguments>  <options>

project, library and app

cliq supports a library with multiple command line apps:

$ cliq create project ./myproj --name mylib --cli myapp,yourapp
$ pip install -e ./mylib
$ myapp -h
$ yourapp -h

See the directory structure: project, library and apps.

$ tree myproj
myproj
├── README.md
├── mylib
│   ├── __init__.py
│   ├── myapp
│   │   ├── __init__.py
│   │   └── main
│   │       ├── __init__.py
│   │       └── command
│   │           ├── config.py
│   │           ├── help.py
│   │           └── init.py
│   └── yourapp
│       ├── __init__.py
│       └── main
│           ├── __init__.py
│           └── command
│               ├── config.py
│               ├── help.py
│               └── init.py
├── setup.cfg
└── setup.py

7 directories, 14 files

Simple command

Generate a simple command template script file:

$ cliq create command say.py  
$ python say.py -h
usage: __main__ [-h]

options:
  -h, --help  show this help message and exit

Add arguments to self.parser and implement run method:

class Command(SimpleCommand):
    def __init__(self, app = None, name = __name__):
        super().__init__(app, name)
        
        self.parser.add_argument('something', type=str, help='something')
        
    def run(self, argv):
        args = self.parser.parse_args(argv)
        print(args.something)

Use it:

$ python say.py hello
hello

Complex command with nested subcommands

Create a command script file with the subcommands option:

$ cliq create command do.py --with-subcommands something,anything,nothing 

Test it:

$ python do.py
usage: __main__ [-h] {something,anything,nothing} ...

options:
  -h, --help            show this help message and exit

subcommands:
  {something,anything,nothing}
                        command help
    something           something
    anything            anything
    nothing             nothing

Edit it and put it into the command directory:

$ mv do.py myapp/myapp/main/command/

Project with multiple command line modules

You can create a project with multiple command line interface modules.

$ cliq create project ./holy --with-cli graham,terry 
$ pip install -e ./holy

Directory strucutre:

holy/
└── holy
    ├── graham
    │   └── main
    │       └── command
    └── terry
        └── main
            └── command

Test cli modules:

$ graham -h 
...

$ terry -h 
...

Add commands:

$ cliq create command holy/holy/graham/main/command/say.py
$ graham say -h

$ cliq create command holy/holy/graham/main/command/play.py --sub role,instrument
$ graham play role -h
$ graham play instrument -h

Simple command line apps

A command line module can run without predefined commands. Just put your command script named __init__.py into the path <app>/main/command/.

myapp/
├── __init__.py
└── main
    ├── __init__.py
    └── command
        └── __init__.py

For example, you are going to write a image library with command line converters.

$ cliq create project myimglib --cli png2jpg,jpg2png
$ pip install -e ./myimglib/
$ cliq create command myimglib/myimglib/png2jpg/main/command/__init__.py
$ png2jpg --help

Open __init__.py and write your code. png2jpg runs the code in __init__.py. Remove default command scripts if you don't need them.

$ rm myimglib/myimglib/png2jpg/main/command/*
$ cliq create command myimglib/myimglib/png2jpg/main/command/__init__.py