Lists in ConfigParser

Breaking up long lists

If your list could stretch from here to the moon, split it over multiple lines. This keeps your config files readable, even if they're longer than a python (the snake, not the programming language 🐍).

Example:

import configparser, json

config = configparser.ConfigParser()
config['LongList'] = {
    'many_numbers': json.dumps(
        [
            1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 
            # Even Fibonacci loves how this sequence is progressing
            11, 12, 13, 14, 15, 16, 17, 18, 19, 20
        ])
}

# Hand this to NASA, your list is now spaciously formatted and ready for launch!
with open('longlist.ini', 'w') as f:
    config.write(f)


Universal default values

The [DEFAULT] section is like a phone a friend lifeline in a game-show! It allows values to be shared across different sections. This works wonders for common list defaults.

Example:

[DEFAULT]
# The following numbers may or may not unlock a secret treasure chest
default_numbers = [1, 2, 3]


List organization within ConfigParser

For multiple lists, dedicate specific sections for each with unique key-value pairs. Use config.items("section_name") to retrieve list items effectively.

Example:

import configparser, json

config = configparser.ConfigParser()
config['Fruits'] = {'apples': 10, 'oranges': 20, 'bananas': 30}
config['Vegetables'] = {'carrots': 15, 'tomatoes': 25}

# Vegans, look no further for your shopping list!
with open('grocery.ini', 'w') as f:
    config.write(f)

# Returns a list of tuples: the Ying and Yang of Python data structures
fruits = config.items('Fruits')


Delimited Strings and Lists

Opt for delimiter-separated strings when storing lists. Choose any safe delimiter that isn't present in your list items and split the string to retrieve the original items for the list.

Example:

# Storing a list with delimiter
config['Settings'] = {
  # RGB or bust!
  'colors': 'red|green|blue'
}

# Somewhere over the String Rainbow 🌈
colors = config['Settings']['colors'].split('|')


Advanced Alternatives

YAML: If you crave for simplicity and readability, YAML might just be your favorite dish. It has native support for lists and even complex structures.

Custom parser: When complexity walks in, a custom parser might be your knight in shining armor. It comes handy for handling reserved configuration abilities.

Environment variables: Sometimes, less is more. Using environment variables for the list-like data can make the whole development process a walk in the park.