Pygredients

Version 0.1.3

Pygredients is an open-source Python library for data structures, algorithms and design patterns available on PyPi. 🍎🍊🍋🫐

Installation

You can install Pygredients using pip:

pip install pygredients

For macOS users, please use the following command:

pip3 install pygredients

Usage

To use Pygredients in your Python code, import it as follows:

import pygredients

Data Structures

Linked List

You can create a linked list, add nodes to it, remove nodes from it, and perform other operations using the LinkedList class.

# Create a linked list
ll = LinkedList()

# Add a node to the linked list
ll.append(1)
ll.append(2)
ll.append(3)

# Remove a node from the linked list
ll.remove(2)  # 2

# Check if a value is in the linked list
ll.contains(1)  # True

# Get the head of the linked list
ll.peek()  # 3

# Get the length of the linked list
ll.size()  # 2

# Check if the linked list is empty
ll.is_empty()  # False

# Print the linked list
print(ll)  # [1, 3]

# Limit the length of the linked list
ll.limit = 2
ll.append(4)  # ValueError: Cannot append 4 to Linked List as it is full.

Stack

You can create a stack, push values onto it, pop values from it, and perform other operations using the Stack class.

# Create a stack
stack = Stack()

# Push a value to the stack
stack.push(1)
stack.push(2)
stack.push(3)

# Pop a value from the stack
stack.pop()  # 3

# Peek the top of the stack
stack.peek()  # 2

# Check if a value is in the stack
stack.contains(1)  # True

# Get the length of the stack
stack.size()  # 2

# Check if the stack is empty
stack.is_empty()  # False

# Print the stack
print(stack)  # [1, 2]

# Limit the length of the stack
stack.limit = 2
stack.push(4)  # ValueError: Cannot push 4 to Stack as it is full.

Queue

You can create a queue, enqueue values into it, dequeue values from it, and perform other operations using the Queue class.

# Create a queue
queue = Queue()

# Enqueue a value to the queue
queue.enqueue(1)
queue.enqueue(2)
queue.enqueue(3)

# Dequeue a value from the queue
queue.dequeue()  # 1

# Peek the front of the queue
queue.peek()  # 2

# Check if a value is in the queue
queue.contains(1)  # True

# Get the length of the queue
queue.size()  # 2

# Check if the queue is empty
queue.is_empty()  # False

# Print the queue
print(queue)  # [2, 3]

# Limit the length of the queue
queue.limit = 2
queue.enqueue(4)  # ValueError: Cannot enqueue 4 to Queue as it is full.

Design Patterns

Observer

The Observer pattern is implemented in Pygredients using theObserver and Observable classes. Here's an example usage:

from pygredients.observer.observer import Observer, Observable


class WeatherStation(Observable):
    pass


class DisplayDevice(Observer):
    def __init__(self, name):
        super().__init__(name)
        self.temperature = None

    def notify(self, *args, **kwargs):
        self.temperature = kwargs.get('temperature')
        print(f'{self.name} now displays the temperature: {self.temperature}°C')


# Initialize a WeatherStation and two DisplayDevices
station = WeatherStation()
device1 = DisplayDevice("Device1")
device2 = DisplayDevice("Device2")

# Register the DisplayDevices with the WeatherStation
station.register_observers(device1)
station.register_observers(device2)

# Update the state of the WeatherStation
station.state = {'temperature': 20}

# Unsubscribe device1 and update the state again
device1.unsubscribe()
station.state = {'temperature': 22}