Pathfinding algorithms for python 3.
Currently there are 7 path-finders bundled in this library, namely:
Dijkstra and A* take the weight of the fields on the map into account.
If you are still using python 2 take a look at the (unmaintained) python2-branch.
This library is provided by pypi, so you can just install the current stable version using pip:
pip install pathfinding
For usage examples with detailed descriptions take a look at the docs folder, also take a look at the test/ folder for more examples, e.g. how to use pandas
While running the pathfinding algorithm it might set values on the nodes. Depending on your path finding algorithm things like calculated distances or visited flags might be stored on them. So if you want to run the algorithm in a loop you need to clean the grid first (see Grid.cleanup
). Please note that because cleanup looks at all nodes of the grid it might be an operation that can take a bit of time!
All pathfinding algorithms in this library are inheriting the Finder class. It has some common functionality that can be overwritten by the implementation of a path finding algorithm.
The normal process works like this:
find_path
on one of your finder implementations.init_find
instantiates the open_list
and resets all values and counters.open_list
. This list gets filled with all nodes that will be processed next (e.g. all current neighbors that are walkable). For this you need to implement check_neighbors
in your own finder implementation.check_neighbors
you first want to get the next node closest from the current starting point from the open list. the next_node
method in Finder does this by giving you the node with a minimum f
-value from the open list, it closes it and removes it from the open_list
.find_neighbors
. This just calls grid.neighbors
for most algorithms.process_node
process_node
calculates the cost f
from the start to the current node using the calc_cost
method and the cost after calculating h
from apply_heuristic
.process_node
updates the open list so find_path
can run check_neighbors
on it in the next node in the next iteration of the main loop.flow:
find_path
init_find # (re)set global values and open list
check_neighbors # for every node in open list
next_node # closest node to start in open list
find_neighbors # get neighbors
process_node # calculate new cost for neighboring node
You can run the tests locally using pytest. Take a look at the test
-folder
You can follow below steps to setup your virtual environment and run the tests.
# Go to repo
cd python-pathfinding
# Setup virtual env and activate it - Mac/Linux for windows use source venv/Scripts/activate
python3 -m venv venv
source venv/bin/activate
# Install test requirements
pip install -r test/requirements.txt
# Run all the tests
pytest
Please use the issue tracker to submit bug reports and feature requests. Please use merge requests as described here to add/adapt functionality.
python-pathfinding is distributed under the MIT license.
Andreas Bresser, self@andreasbresser.de
Authors and contributers are listed on github.
Inspired by Pathfinding.JS