cmdpackage 0.1.6

Automated python package generator for CLI function calls

Command Package (cmdpackage)

Table of Contents

• Command Package (cmdpackage)
  • Table of Contents
  • Introduction
  • Standard Installation from PyPI
    • Using cmdpackage to Create New Python Packages
    • Modifying New Python Packages
      • Install New Editable Python Package
  • Editable cmdpackage Installation
    • Automated Default New Package Setup with cmdpackage.sh

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Introduction

cmdpackage is a pip package that generates opinionated Python command-line program packages. These derived program packages automate the creation of new CLI program commands that you can modify in a development environment. cmdpackage can be installed as a standard (or "production") installation or as an editable (or "development") installation directly from GitHub.

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Standard Installation from PyPI

A standard installation allows a user to quickly create derived program packages.

pip install cmdpackage

The derived program packages will be modified in a virtual Python development environment using virtualenv. This virtual environment is isolated as a self-contained Python installation with its own site-packages directory. This isolation prevents dependency conflicts between different projects.

pip install virtualenv

Using cmdpackage to Create New Python Packages

Once installed, you can create a package directory for your new Python package (e.g., myTypes) and run cmdpackage to generate the necessary files within this directory.

mkdir $HOME/myTypes
cd $HOME/myTypes
cmdpackage

You will be asked standard package generation questions:

name (myTypes):
version (0.1.0):
description (myTypes pip package):
readme ():
license (MIT License):
authors (username):
authorsEmail ([e-mail]):
maintainers (username):
maintainersEmail ([e-mail]):
classifiers ():
commit a git repo [Y/n]?:

The default input for each question is the bracketed value. The username will be set to your global Git config name if Git is present; otherwise, your system login username will be used.

Modifying New Python Packages

You're now ready to work on your new Python package, myTypes, by first activating a Python virtual development environment.

• Activation Process: To use a virtual environment, you must activate it. This is typically done by running a script within the environment's directory:

  • On Linux/macOS: source /path/to/myTypes/env/bin/activate
  • On Windows: /path/to/myTypes/env/Scripts/activate (Not tested on Windows)

  Activating the environment modifies your terminal's shell session, primarily by adjusting your PATH environment variable. This ensures that when you type python or pip, you are using the Python interpreter and package manager from within that specific virtual environment, rather than your system's global Python.

  Deactivation Process: When you deactivate a virtual environment, you return to the System/Global Python Environment.

  • Execute: deactivate

Install New Editable Python Package

pip install -e .

Executing pip list results in the following output, showing the localized package installation in the Python virtual environment:

Package    Version Editable project location
---------- ------- -----------------------------------
myTypes    0.1.0   /Users/<username>/proj/python/myTypes
pip        25.1.1
setuptools 80.9.0
wheel      0.45.1

Your new myTypes program is now ready to use as a launching point for your Python CLI development. A list of installed commands can be found using:

myTypes -h

To add a new command named type – which will record a token, a title representing the type of information this token represents, and a short description of what it is and where it can be used – use the following command:

myTypes newCmd type token title sd

You will then be prompted to enter help text for the command and each of the arguments you defined (type, title, sd):

1. Enter a description of the 'type' command: Records a token that represents a type of data or information.
2. Enter a description of the 'token' argument: The token that represents a type of data or information.
3. Enter a description of the 'title' argument: The title of the token that represents a type of data or information.
4. Enter a description of the 'sd' argument: A short description of the type of data or information is entered for sd.

Run the new myTypes type command:

myTypes type int integer 'An integer is a whole number that can be positive, negative, or zero.'

The path to the Python file that needs your modification (type.py) is displayed as output, along with the values of the three arguments (type, title, sd):

DEBUG: Modify default behavior in src/myTypes/commands/type.py
INFO: token: int
INFO: title: integer
INFO: sd: An integer is a whole number that can be positive, negative, or zero.

The rmCmd is used to remove a command from your myTypes program.

myTypes rmCmd run

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Editable cmdpackage Installation

Modifying a clone of the cmdpackage GitHub repository allows a developer to change the initial files of new commands added to cmdpackage derived Python packages. The following commands are used to clone and install cmdpackage in a virtual environment for this purpose:

mkdir $HOME/proj
cd  $HOME/proj
git clone https://github.com/mpytel/cmdpackage.git
cd cmdpackage
pip install -e .

We purposely installed cmdpackage in the System/Global Python Environment. cmdpackage is then used to generate program packages that run in Virtual Python Environments set up by cmdpackage when run in a new Python package directory for modification in a development environment. This is performed using the commands described in the two above sections:

1. Creating a new package
2. Modifying new python packages

Automated Default New Package Setup with cmdpackage.sh

A shell script (cmdpackage.sh) is provided in the cmdpackage directory to automate the creation of a new package using default setup values. This script creates and changes the working directory to one named after your program package. It then creates and activates a virtual environment within this directory, and installs the cmdpackage pip package from the local repository. It then creates the new package and uninstalls cmdpackage from the new package's virtual environment. The new package is installed and run to create a 'helloWorld' command to test and illustrate the newCmd command that is provided with the new derived package.

From any directory, execute the following command to run this shell script:

source $HOME/proj/python/cmdpackage/cmdpackage.sh myPack

If you prefer not to use the cmdpackage.sh shell script, the manual command steps used to create/install/use a new package (myPack) with a new 'helloWorld' command are:

mkdir myPack
cd myPack
virtualenv env/myPack
source env/myPack/bin/activate
pip install $HOME/proj/python/cmdpackage
cmdpackage
   # Press the return key 11 times to accept the default values.
pip uninstall cmdpackage
   # Press the return key to accept the default value Y.
pip install -e .
myPack newCmd helloWorld greeting
   # When prompted by 'Enter help description for helloWorld:'
   # enter: 'Echo the greeting text.'
   # When prompted by 'Enter help description for greeting:'
   # enter: 'The text to echo.'
myPack helloWorld "You're ready to add and remove commands, and modify code in your myPack project!"

The following output results from executing myPack helloWorld:

DEBUG: Modify default behavior in src/myPack/commands/helloWorld.py
INFO: greeting: You're ready to add and remove commands, and modify code in your myPack project!