NewsPaper Bill Calculator

This app calculates your monthly newspaper bill. Requires SQLite>=3.35 (and Python>=3.9 if you intend to develop anything, instead of just using the executables).

Key concepts

1. Each newspaper has a certain cost per day of the week
2. Each newspaper may or may not be delivered on a given day
3. Each newspaper has a name, and a number called a key
4. You may register any dates when you didn't receive a paper in advance using the addudl command
5. Once you calculate, the results are displayed and logged.

Installation

1. From the latest release, download the "updater" file for your operating system in any folder, and make it executable.

   Recommended locations, where the CLI will always download.

   OS	Location
   Linux	~/bin/npbc/npbc
   macOS	~/Applications/npbc/npbc
   Windows	~\.npbc\bin\npbc.exe

2. Run the following command:

   /path/to/updater update

3. You can now run path/to/updater init to begin.

 

Alternatively, just run these scripts. You'll need to have wget installed.

For Linux systems, run:

mkdir -p ~/bin/npbc
wget https://github.com/eccentricOrange/npbc/releases/latest/download/npbc_updater-linux-x64 -O ~/bin/npbc/npbc
chmod +x ~/bin/npbc/npbc
~/bin/npbc/npbc init
echo "alias npbc=\"~/bin/npbc/npbc\"" >> ~/.bashrc
exec "$SHELL"

For macOS systems, run:

mkdir -p ~/Applications/npbc
wget https://github.com/eccentricOrange/npbc/releases/latest/download/npbc_updater-macos-x64 -O ~/Applications/npbc/npbc
chmod +x ~/Applications/npbc/npbc
~/bin/Applications/npbc init
echo "alias npbc=\"~/Applications/npbc/npbc\"" >> ~/.bashrc
exec "$SHELL"

For Windows systems, run the following from PowerShell and add ~\.npbc\bin to PATH:

mkdir -p "~\.npbc\bin";
wget https://github.com/eccentricOrange/npbc/releases/latest/download/npbc_updater-windows-x64.exe -O "~\.npbc\bin\npbc.exe";
& "~\.npbc\bin\npbc.exe" init;

Detailed explanations

What is this?

This application helps you calculate monthly newspaper bills. The goal is to generate a message that I can paste into WhatsApp and send to my newspaper vendor. The end result here is a CLI tool that will be later used as a back-end to build GUIs (hence learn about: C#, HTML/CSS/JS, Flutter). In its current form, everything will be "compiled" by PyInstaller into one-file stand-alone executables for the end-user using GitHub Actions.

The other important goal was to be a testbed for learning a bunch of new tools: more Python libraries, SQL connectors, GitHub Actions (CI/CD, if I understand correctly), unit tests, CLI libraries, type-hinting, regex. I had earlier built this on a different platform, so I now have a solid idea of how this application is used.

What files exist?

(ignoring conventional ones like README and requirements.txt)

File	Purpose/Description
npbc_core.py	Provide the core functionality: the calculation, parsing and validation of user input, interaction with the DB etc. Later on, some functionality from this will be extracted to create server-side code that can service more users, but I have to learn a lot more before getting there.
npbc_regex.py	Contains all the regex statements used to validate and parse user input.
npbc_exceptions.py	Defines classes for all the custom exceptions used by the core and the CLI.
npbc_cli.py	Import functionality from npbc_core.py and wrap a CLI layer on it using argparse. Also provide some additional validation.
npbc_updater.py	Provide a utility to update the application on the user's end.
test_core.py	Test the functionality of the core file (pytest), except anything to do with the database.
test_db.py	Test the functionality of the core file (pytest), for anything to do with the database.
test_regex.py	Test the functionality of the regex statements.
data/schema.sql	Database schema. In my local environment, the data folder also has a test database file (but I don't want to upload this online).
data/test.sql	SQL statements to generate test data for test_db.py.
test.dockerfile	Provide an environment for the PyTest to run, because the project needs SQLite>=3.35, which does not ship with most stable Debian Bullseye or Ubuntu 20 systems. This is available as built image from Docker Hub as eccentricorange/npbc:test.