Script entrypoints

Description

Script entrypoints are useful for allowing you to write scripts that can be accessed anywhere on the machine. They are setup in the setup.py file of your python package.

Usage

In this repo you can see the demo code and actually run it using the steps below 1. Install as a pip package using pip install . 2. In your terminal type command_name (literally command_name, this is not a placeholder) 3. The help text for the command will appear, and this can be run in any folder on your computer.

Note that to uninstall the script you need to type pip uninstall entrypoint-demo

Real World Example

Lets say you are writing a utility to download a youtube video, you want this to be callable from anywhere in the OS by typing $ yt-downloader --url="<video URL>".

To do this you would have a line in your setup.py file to specify

setuptools.setup(
    # Some setup info

    entry_points={
          'console_scripts': ['yt-downloader = package.youtube:downloader']
      },

    # More setup info

This can be seen in full detail with the PyTube module

import setuptools def get_content(filename): """ Gets the content of a file and returns it as a string Args: filename(str): Name of file to pull content from Returns: str: Content from file """ with open(filename, "r") as full_description: content = full_description.read() return content setuptools.setup( name="entrypoint demo", version="0.0.1", author="Kieran Wood", author_email="[email protected]", description="A demo for script entrypoints", long_description=get_content("readme.md"), long_description_content_type="text/markdown", url=r"https://github.com/canadian-coding/posts/2019/June/June%2023rd%20-%20Python%20Entrypoints", packages=setuptools.find_packages(), entry_points={ 'console_scripts': ['command_name = package.command_line_utility:main'] }, classifiers=[ "Programming Language :: Python :: 3", "Operating System :: OS Independent", ], )

This file is empty and just used to mark the folder package as a module

""" Description: An example command line utility intended to be useable in any part of the OS. Once installed\ You should be able to run the $ <command_name> the same way as you would run $ command_line_utility.py Example: $ command_name -h """ import argparse # Used to create an argument parser import sys # Used to check if any arguments have been provided def main(): """The main function where everything lives, you need a function to point the entrypoint to so it can\ be run. """ # Setting up Main Argument Parser main_parser = argparse.ArgumentParser(description="A demo of python entrypoint") main_parser.add_argument("-v",'--version', action='version', version='command_name V0.0.1') # Setting up the main subparser subparsers = main_parser.add_subparsers(help="This is the help command, it is called by using -h or --help") example_command = subparsers.add_parser('example_command', help='An example with some help text') # Print help if no argument is provided if len(sys.argv)==1: main_parser.print_help() args = main_parser.parse_args()