How can I implement Dijkstra's algorithm in Python?

How can I implement Dijkstra's algorithm in Python?

You can implement Dijkstra's algorithm using a priority queue. Would you like to see a code example?

Yes, please provide a code example.

Here's a simple implementation:

import heapq

class Graph:
    def __init__(self):
        self.edges = {}

    def add_edge(self, from_node, to_node, weight):
        if from_node not in self.edges:
            self.edges[from_node] = []
        self.edges[from_node].append((to_node, weight))

    def dijkstra(self, start):
        queue = [(0, start)]
        distances = {start: 0}
        while queue:
            current_distance, current_node = heapq.heappop(queue)
            if current_distance > distances.get(current_node, float('inf')):
                continue
            for neighbor, weight in self.edges.get(current_node, []):
                distance = current_distance + weight
                if distance < distances.get(neighbor, float('inf')):
                    distances[neighbor] = distance
                    heapq.heappush(queue, (distance, neighbor))
        return distances

What are the key components of this implementation?

The key components are the graph representation, the priority queue for selecting the next node, and the distance tracking for each node.