hashtable-nicolerg

HashTable

This simple package provides a custom implementation of a hash table in Python, created by following this tutorial written by Bartosz Zaczyński. The HashTable class replicates many methods from Python dictionaries, including HashTable.clear() and HashTable.update().

Installation

This package is available in PyPI. Use the package manager pip to install HashTable.

python3 -m pip install hashtable-nicolerg

Alternatively, experiment with HashTable in a Docker container.

Usage

from hashtable_nicolerg.hashtable import HashTable

# Create an instance of HashTable with initial size 10
# and loading factor threshold 0.5, meaning the HashTable
# will be resized to have 2x capacity whenever the number of 
# key-value pairs is at least half the current capacity
hash_table = HashTable(capacity=10, load_factor_threshold=0.5)

hash_table["blue"] = "sea"              # Add key-value pair "blue":"sea"
hash_table["list"] = [1,2,3]            # Add key-value pair with a mutable value 
len(hash_table)                         # Return number of key-value pairs
hash_table.capacity                     # Return current capacity
hash_table.load_factor                  # Return current load factor
hash_table.keys                         # Return set of keys
hash_table.values                       # Return list of values 
hash_table.pairs                        # Return list of key-value pairs
del hash_table["list"]                  # Delete key-value pair for specified key
hash_table.update({"blue":"0000FF"})    # Update value for key "blue" using a dictionary
hash_table["blue"]                      # Return value for key "blue"
hash_table.clear()                      # Remove all key-value pairs 

Motivation

Developing this package reinforced knowledge in the following areas:

• Python classes, including dunder methods
• Hash table implementation, including handling hash collisions
• Testing, including TDD, unit tests, and pytest
• Developing Python packages

Dev notes

1. Create the recommended directory structure and populate files
2. Build the package in the same directory as pyproject.toml, which should create a dist/ directory

   python3 -m build
   

3. Use Twine to upload the package to PyPI

   python3 -m pip install --upgrade twine
   python3 -m twine upload dist/*
   

4. Install your newly uploaded package

   python3 -m pip install hashtable-nicolerg
   

5. To update the package, increment the version in `pyproject.toml``, build, and upload

   python3 -m build
   python3 -m twine upload --skip-existing dist/*
   

6. Install and test your new version

   python3 -m pip install hashtable-nicolerg --upgrade