Dijkstar

2.6.0 verified Fri May 01 auth: no python

Dijkstar is an implementation of Dijkstra's single-source shortest paths algorithm and the A* algorithm for weighted multigraphs. Current version 2.6.0 (release frequency: occasional). It is simple to use and allows custom graph structures.

pip install dijkstar

Common errors

error AttributeError: module 'dijkstar' has no attribute 'Graph' ↓

cause Importing incorrectly (e.g., import dijkstar then dijkstar.Graph) or having a different version where Graph is not top-level.

fix

Use: from dijkstar import Graph

error KeyError: node not in graph ↓

cause Attempting to find a path from or to a node that has not been added to the graph.

fix

Ensure all nodes in the path query are present in the graph.

Warnings

gotcha Graph is a multigraph; adding multiple edges between the same nodes with different costs is allowed and may lead to unexpected shortest paths if not careful. ↓

fix Ensure that duplicate edges with unintended costs are not added inadvertently.

gotcha Node IDs must be hashable; using unhashable types (like lists) as nodes will raise an error. ↓

fix Use hashable node types such as integers, strings, or tuples.

Imports

Graph
```
from dijkstar import Graph
```
Correct import for the Graph class.
find_path
```
from dijkstar import find_path
```
Correct import for the pathfinding function.

Quickstart

Create a weighted graph and find the shortest path between two nodes.

from dijkstar import Graph, find_path

graph = Graph()
graph.add_edge(1, 2, 100)
graph.add_edge(2, 3, 200)

path_info = find_path(graph, 1, 3)
print('Shortest path:', path_info.nodes)
print('Total cost:', path_info.total_cost)