Working with INI Files in Python

General Discussions
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1

How can I read, write, and create an INI file with Python3?

I have an INI file, FILE.INI, with the following content:

default_path = "/path/name/"
default_file = "file.txt"

In Python, I want to:

  1. Read the file and create it if it doesn’t exist.
  2. Retrieve the value of default_path.
  3. Update or append new values to the INI file.

Here’s what I expect to do in the Python file:

# Read file and create if it doesn't exist
config = iniFile('FILE.INI')

# Get "default_path"
print(config.default_path)  # Should print "/path/name/"

# Create or Update
config.append('default_path', 'var/shared/')
config.append('default_message', 'Hey! help me!!')

The updated FILE.INI should look like:

default_path    = "var/shared/"
default_file    = "file.txt"
default_message = "Hey! help me!!"

How can I achieve this in Python, specifically for handling Python ini file operations?

2

If you’re new to handling INI files in Python, the built-in configparser module is a great place to start. It’s simple, efficient, and requires no additional installations. Here’s an example:

import configparser

# Initialize the config parser
config = configparser.ConfigParser()

# Read the INI file (or create it if it doesn’t exist)
config.read('FILE.INI')

# Access the 'default_path' value
print(config['DEFAULT']['default_path'])  # Output: "/path/name/"

# Update the 'default_path' value
config['DEFAULT']['default_path'] = '/var/shared/'

# Add a new entry for 'default_message'
config['DEFAULT']['default_message'] = 'Hey! help me!!'

# Save the changes back to the INI file
with open('FILE.INI', 'w') as configfile:
    config.write(configfile)

This should update your FILE.INI file as expected. Want more advanced handling? Let’s dive into alternative libraries next.

3

If you’re comfortable using a third-party library, ConfigObj offers a more intuitive and user-friendly interface for managing INI files. Plus, it comes with features like automatic type conversion! Here’s how to use it:

from configobj import ConfigObj

# Load the INI file (or create it if it doesn’t exist)
config = ConfigObj('FILE.INI')

# Retrieve the value of 'default_path'
print(config['default_path'])  # Output: "/path/name/"

# Update 'default_path' and add a new key-value pair
config['default_path'] = '/var/shared/'
config['default_message'] = 'Hey! help me!!'

# Save changes back to the INI file
config.write()

To install ConfigObj, simply run:

pip install configobj

This library is particularly handy if you want less verbosity compared to configparser. Need to work with sections in your INI file? The next example has you covered.

4

When your INI file has multiple sections, you can manage them easily using configparser. This is especially useful for larger or more organized configurations. Let me show you:

import configparser

# Initialize the ConfigParser
config = configparser.ConfigParser()

# Read the INI file
config.read('FILE.INI')

# Access and print the value of 'default_path' in the 'Settings' section
print(config['Settings']['default_path'])  # Output: "/path/name/"

# Update the 'default_path' and add a new key 'default_message' in 'Settings'
config['Settings']['default_path'] = '/var/shared/'
config['Settings']['default_message'] = 'Hey! help me!!'

# Save the updated file
with open('FILE.INI', 'w') as configfile:
    config.write(configfile)

This approach makes it easy to organize your INI files with sections like [Settings], [User Preferences], etc. Just ensure you structure your INI file properly to reflect these sections.