Shopping List - Do More, Pay Less

shopping_list is a simple tool to calculate the cost breakdown and total of a shopping list containing items in multiple categories.

It allows to create different variation of prices, to compare the influence in the total cost.
See the corresponding section Pro Tip - Price combinations

shopping_list in action

The project was originally created to estimate the total cost of devices in a Home-Automation project and see the influence of different purchase decisions.

Given:

• A list of prices
• A shopping list of items per category (per room in the example)

It generates an output breaking down the costs.

> shoppinglist shopping_list.yaml prices.yaml 
Total cost breakdown
---
Living Room: 77.5 €
Kitchen: 45 €
Extra: 15 €
---
Total: 137.5 €

With shopping_list.yaml

Living-room:
  - InWallSwitch
  - InWallSwitch
  - PaddleSwitch
  - MotionSensor
Kitchen:
  - BulbBasic
  - BulbAmbiance
Extra:
  - Shipping

And prices.yaml

InWallSwitch: 26
PaddleSwitch: 15
MotionSensor: 10.5
BulbBasic: 15
BulbAmbiance: 30
Shipping: 15

Demo versions of these files can be find under demo/

cd demo
shoppinglist shopping_list.yaml prices.yaml

Usage

Installation

pip3 install shoppinglist
# Or
pip3 install --user shoppinglist

Warning: Use python 3!

Usage

Usage: shoppinglist [OPTIONS] SHOPPING_LIST_FILE PRICES_FILE
                    [PRICE_OVERRIDES_FILES]...
Options:
  --with-count         Display the count for each item
  --without-breakdown  Hide the cost breakdown for each category
  --help               Show this message and exit.

Arguments

SHOPPING_LIST_FILE

• The shopping list
• shopping_list.yaml in the previous examples

PRICES_FILE

• The base prices
• prices.yaml in the previous examples

[PRICE_OVERRIDES_FILES]

• Zero or multiple price overrides files
• A price override has the same format as the PRICES_FILE file
• PRICE_OVERRIDES_FILES define prices overridings the base prices present in PRICES_FILE
• Kinda like mixins for the price list
• In case of multiple overrides, only the last one is taken into account

Format for the files

prices.yaml and price_overrides_*.yaml

• 1 item per line, with its price
• See example

shopping_list.yaml

• 1 block per category
• Each block contains a list on items
• Item prices must have been defined in prices.yaml
• Duplicates allowed, they will be counted twice
• See example

Pro Tip - Price combinations

Create different combination of prices to see quickly see the influence of your purchase decisions.

To do so, you have 2 options:

• Define multiple base prices
• Define a base price and override individual items

Using multiple base prices

For instance amazon.yaml

InWallSwitch: 56 <- More expensive InWallSwitch
PaddleSwitch: 7  <- Cheaper PaddleSwitch
MotionSensor: 10.5
BulbBasic: 15
BulbAmbiance: 30
Shipping: 0      <- Free shipping

Or upgrade_basic_to_ambiance.yaml

InWallSwitch: 26
PaddleSwitch: 15
MotionSensor: 10.5
BulbBasic: 30     <- Bump the price of 'basic' bulb to match
BulbAmbiance: 30     the one of the 'ambiance' variation
                     and see how it affects the Total!
Shipping: 15

Results

# In 'demo/' folder
> shoppinglist shopping_list.yaml prices.yaml
...
Total: 137.5 €
> shoppinglist shopping_list.yaml amazon.yaml 
...
Total: 174.5 €
> shoppinglist shopping_list.yaml upgrade_basic_to_ambiance.yaml
...
Total: 152.5 €

Using prices overrides

With base prices.yaml

InWallSwitch: 26
PaddleSwitch: 15
MotionSensor: 10.5
BulbBasic: 15
BulbAmbiance: 30
Shipping: 15

First override free_shipping.yaml

Shipping: 0 <- Free shipping

Second override tradfri_bulb_instead_of_hue.yaml

BulbBasic: 10    <- Cheaper Bulbs
BulbAmbiance: 20 <- Cheaper Bulbs

Results

# In 'demo/' folder
> shoppinglist shopping_list.yaml prices.yaml
...
Total: 137.5 €
> shoppinglist shopping_list.yaml prices.yaml free_shipping.yaml
...
Total: 122.5 €
> shoppinglist shopping_list.yaml prices.yaml free_shipping.yaml tradfri_bulb_instead_of_hue.yaml
...
Total: 107.5 €

Development

Prerequisites: Pipenv

This project needs pipenv in order to work.

If you haven’t set it up already… please do yourself a favor and read about it. That thing made my life just slightly better… but to the point where I actually notice an increase in my mood while working with python projects.
Kudos to them :)

More info on: Pipenv: Python Development Workflow for Humans

Interested in having that setup automatically for you?
Then check out my ansible role that does just that ;)
==> FlorianKempenich.python-virtualenv

Installation

git clone git@github.com:FlorianKempenich/Shopping-List.git
cd Shopping-List
pipenv install --dev
pipenv shell

Tests

pytest
# Or
./start_tdd.sh

Author Information

Follow me on Twitter: @ThisIsFlorianK
Find out more about my work: Florian Kempenich - Personal Website