KeepDelta

Efficient Delta Management for Python Data Structures

A lightweight Python library for creating and applying deltas (differences) between two native Python data structures. This is useful for tracking changes in nested data structures such as dictionaries, lists, tuples, sets, and more.

Features

• Generate compact delta objects that describe differences between two Python data structures.
• Apply a delta to an original data structure to reconstruct the updated version.
• Supports native Python data structures: dict, list, tuple, set, int, float, bool, str, and more.
• Handles deeply nested and mixed data structures efficiently.

Installation

Install the package using pip:

pip install keepdelta

Usage

1. Create Delta The create function generates a delta object that captures the differences between two data structures.

Example:

import keepdelta as kd

# Initial data
old = {
    "info": {
        "name": "Alice",
        "age": 30,
        "is_student": True,
        "preferences": (
            "chocolate", 
            {"sports": {"football", "tennis"}},
        ),
    }
}

# Updated data
new = {
    "info": {
        "name": "Alice",
        "age": 31,
        "is_student": False,
        "preferences": (
            "coffee", 
            {"sports": {"football", "bodybuilding"}},
        ),
    }
}

# Create delta
delta = kd.create(old, new)
print(delta)

Output:

{
    "info": {
        "is_student": False,
        "age": 1,
        "preferences": {
            0: "coffee",
            1: {"sports": {0:"football", 1: "bodybuilding"}}
        }
    }
}

2. Apply Delta The apply function takes an original data structure and a delta, then applies the delta to recreate the updated structure.

Example:

# Apply delta
updated = kd.apply(old, delta)

# Verify the update
print(updated == new)  # Output: True

How It Work

1. create(old, new):

• Compares the old and new data structures.
• Produces a compact delta object containing only the differences.

2. apply(original, delta):

• Applies the delta to the original data structure.
• Produces the new data structure.

Surpported Formats

KeepDelta supports most of the native Python data structures, ensuring compatibility and flexibility when working with a wide variety of data types. The currently supported structures include:

• Primitive Types:

  • bool – e.g., True, False
  • str – e.g., "hello", "apple"
  • int – e.g., 42, -7
  • float – e.g., 3.14, -0.001
  • complex – e.g., 3 + 4j, -2j

• Collections:

  • dict – e.g., {"key": "value", "age": 30}
  • list – e.g., [1, 2, 3, "hello"]
  • tuple – e.g., (1, "a", 3.14)
  • set – e.g., {1, 2, 3, "apple"}

• Special Features:

  • Nested Structures: Supports deeply nested combinations of these types, such as a dictionary containing lists, tuples, or sets.
  • Mixed Types: Easily handles scenarios where different data types are combined in a single structure.

Contributing

Contributions are welcome! Feel free to:

• Report issues.
• Submit feature requests.
• Create pull requests.

License

Distributed under the MIT License. See LICENSE.txt for more information.