Add A* (A-star) Pathfinding Algorithm with Doctests & Type Hints#13781
Add A* (A-star) Pathfinding Algorithm with Doctests & Type Hints#13781umarprogrammer19 wants to merge 11 commits intoTheAlgorithms:masterfrom
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| import heapq | ||
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| # Type aliases for readability (PEP 585 built-in generics, PEP 604 unions) | ||
| Node = tuple[int, int] |
There was a problem hiding this comment.
Variable and function names should follow the snake_case naming convention. Please update the following name accordingly: Node
| start: Node, | ||
| goal: Node, | ||
| neighbors: NeighborsFn, | ||
| h: HeuristicFn, |
There was a problem hiding this comment.
Please provide descriptive name for the parameter: h
| return None | ||
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| def heuristic(n: Node, goal: Node) -> float: |
There was a problem hiding this comment.
As there is no test file in this pull request nor any test function or class in the file searches/astar.py, please provide doctest for the function heuristic
Please provide descriptive name for the parameter: n
| return abs(x1 - x2) + abs(y1 - y2) | ||
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| def neighbors(node: Node) -> Iterable[tuple[Node, float]]: |
There was a problem hiding this comment.
As there is no test file in this pull request nor any test function or class in the file searches/astar.py, please provide doctest for the function neighbors
There was a problem hiding this comment.
Click here to look at the relevant links ⬇️
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Repository:
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Automated review generated by algorithms-keeper. If there's any problem regarding this review, please open an issue about it.
algorithms-keeper commands and options
algorithms-keeper actions can be triggered by commenting on this PR:
@algorithms-keeper reviewto trigger the checks for only added pull request files@algorithms-keeper review-allto trigger the checks for all the pull request files, including the modified files. As we cannot post review comments on lines not part of the diff, this command will post all the messages in one comment.NOTE: Commands are in beta and so this feature is restricted only to a member or owner of the organization.
| from collections.abc import Callable, Iterable | ||
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| # Type aliases (PEP 585 built-in generics, PEP 604 unions) | ||
| Node = tuple[int, int] |
There was a problem hiding this comment.
Variable and function names should follow the snake_case naming convention. Please update the following name accordingly: Node
| start: Node, | ||
| goal: Node, | ||
| neighbors: NeighborsFn, | ||
| h: HeuristicFn, |
There was a problem hiding this comment.
Please provide descriptive name for the parameter: h
| return None | ||
|
|
||
|
|
||
| def heuristic(n: Node, goal: Node) -> float: |
There was a problem hiding this comment.
As there is no test file in this pull request nor any test function or class in the file searches/astar.py, please provide doctest for the function heuristic
Please provide descriptive name for the parameter: n
| return abs(x1 - x2) + abs(y1 - y2) | ||
|
|
||
|
|
||
| def neighbors(node: Node) -> Iterable[tuple[Node, float]]: |
There was a problem hiding this comment.
As there is no test file in this pull request nor any test function or class in the file searches/astar.py, please provide doctest for the function neighbors
There was a problem hiding this comment.
Click here to look at the relevant links ⬇️
🔗 Relevant Links
Repository:
Python:
Automated review generated by algorithms-keeper. If there's any problem regarding this review, please open an issue about it.
algorithms-keeper commands and options
algorithms-keeper actions can be triggered by commenting on this PR:
@algorithms-keeper reviewto trigger the checks for only added pull request files@algorithms-keeper review-allto trigger the checks for all the pull request files, including the modified files. As we cannot post review comments on lines not part of the diff, this command will post all the messages in one comment.NOTE: Commands are in beta and so this feature is restricted only to a member or owner of the organization.
| from collections.abc import Callable, Iterable | ||
|
|
||
| # Type aliases (PEP 585 built-in generics, PEP 604 unions) | ||
| Node = tuple[int, int] |
There was a problem hiding this comment.
Variable and function names should follow the snake_case naming convention. Please update the following name accordingly: Node
| start: Node, | ||
| goal: Node, | ||
| neighbors: NeighborsFn, | ||
| h: HeuristicFn, |
There was a problem hiding this comment.
Please provide descriptive name for the parameter: h
| return None | ||
|
|
||
|
|
||
| def heuristic(n: Node, goal: Node) -> float: |
There was a problem hiding this comment.
As there is no test file in this pull request nor any test function or class in the file searches/astar.py, please provide doctest for the function heuristic
Please provide descriptive name for the parameter: n
| return abs(x1 - x2) + abs(y1 - y2) | ||
|
|
||
|
|
||
| def neighbors(node: Node) -> Iterable[tuple[Node, float]]: |
There was a problem hiding this comment.
As there is no test file in this pull request nor any test function or class in the file searches/astar.py, please provide doctest for the function neighbors
There was a problem hiding this comment.
Click here to look at the relevant links ⬇️
🔗 Relevant Links
Repository:
Python:
Automated review generated by algorithms-keeper. If there's any problem regarding this review, please open an issue about it.
algorithms-keeper commands and options
algorithms-keeper actions can be triggered by commenting on this PR:
@algorithms-keeper reviewto trigger the checks for only added pull request files@algorithms-keeper review-allto trigger the checks for all the pull request files, including the modified files. As we cannot post review comments on lines not part of the diff, this command will post all the messages in one comment.NOTE: Commands are in beta and so this feature is restricted only to a member or owner of the organization.
| from collections.abc import Callable, Iterable | ||
|
|
||
| # Type aliases (PEP 585 built-in generics, PEP 604 unions) | ||
| Node = tuple[int, int] |
There was a problem hiding this comment.
Variable and function names should follow the snake_case naming convention. Please update the following name accordingly: Node
| start: Node, | ||
| goal: Node, | ||
| neighbors: NeighborsFn, | ||
| h: HeuristicFn, |
There was a problem hiding this comment.
Please provide descriptive name for the parameter: h
| return None | ||
|
|
||
|
|
||
| def heuristic(n: Node, goal: Node) -> float: |
There was a problem hiding this comment.
As there is no test file in this pull request nor any test function or class in the file searches/astar.py, please provide doctest for the function heuristic
Please provide descriptive name for the parameter: n
| return abs(x1 - x2) + abs(y1 - y2) | ||
|
|
||
|
|
||
| def neighbors(node: Node) -> Iterable[tuple[Node, float]]: |
There was a problem hiding this comment.
As there is no test file in this pull request nor any test function or class in the file searches/astar.py, please provide doctest for the function neighbors
for more information, see https://pre-commit.ci
There was a problem hiding this comment.
Click here to look at the relevant links ⬇️
🔗 Relevant Links
Repository:
Python:
Automated review generated by algorithms-keeper. If there's any problem regarding this review, please open an issue about it.
algorithms-keeper commands and options
algorithms-keeper actions can be triggered by commenting on this PR:
@algorithms-keeper reviewto trigger the checks for only added pull request files@algorithms-keeper review-allto trigger the checks for all the pull request files, including the modified files. As we cannot post review comments on lines not part of the diff, this command will post all the messages in one comment.NOTE: Commands are in beta and so this feature is restricted only to a member or owner of the organization.
| from collections.abc import Callable, Iterable | ||
|
|
||
| # Type aliases (PEP 585 built-in generics, PEP 604 unions) | ||
| Node = tuple[int, int] |
There was a problem hiding this comment.
Variable and function names should follow the snake_case naming convention. Please update the following name accordingly: Node
| start: Node, | ||
| goal: Node, | ||
| neighbors: NeighborsFn, | ||
| h: HeuristicFn, |
There was a problem hiding this comment.
Please provide descriptive name for the parameter: h
| return None | ||
|
|
||
|
|
||
| def heuristic(n: Node, goal: Node) -> float: |
There was a problem hiding this comment.
As there is no test file in this pull request nor any test function or class in the file searches/astar.py, please provide doctest for the function heuristic
Please provide descriptive name for the parameter: n
| return abs(x1 - x2) + abs(y1 - y2) | ||
|
|
||
|
|
||
| def neighbors(node: Node) -> Iterable[tuple[Node, float]]: |
There was a problem hiding this comment.
As there is no test file in this pull request nor any test function or class in the file searches/astar.py, please provide doctest for the function neighbors
for more information, see https://pre-commit.ci
There was a problem hiding this comment.
Click here to look at the relevant links ⬇️
🔗 Relevant Links
Repository:
Python:
Automated review generated by algorithms-keeper. If there's any problem regarding this review, please open an issue about it.
algorithms-keeper commands and options
algorithms-keeper actions can be triggered by commenting on this PR:
@algorithms-keeper reviewto trigger the checks for only added pull request files@algorithms-keeper review-allto trigger the checks for all the pull request files, including the modified files. As we cannot post review comments on lines not part of the diff, this command will post all the messages in one comment.NOTE: Commands are in beta and so this feature is restricted only to a member or owner of the organization.
| from collections.abc import Callable, Iterable | ||
|
|
||
| # Type aliases (PEP 585 built-in generics, PEP 604 unions) | ||
| Node = tuple[int, int] |
There was a problem hiding this comment.
Variable and function names should follow the snake_case naming convention. Please update the following name accordingly: Node
| start: Node, | ||
| goal: Node, | ||
| neighbors: NeighborsFn, | ||
| h: HeuristicFn, |
There was a problem hiding this comment.
Please provide descriptive name for the parameter: h
| return None | ||
|
|
||
|
|
||
| def heuristic(n: Node, goal: Node) -> float: |
There was a problem hiding this comment.
As there is no test file in this pull request nor any test function or class in the file searches/astar.py, please provide doctest for the function heuristic
Please provide descriptive name for the parameter: n
| return abs(x1 - x2) + abs(y1 - y2) | ||
|
|
||
|
|
||
| def neighbors(node: Node) -> Iterable[tuple[Node, float]]: |
There was a problem hiding this comment.
As there is no test file in this pull request nor any test function or class in the file searches/astar.py, please provide doctest for the function neighbors
Summary
This PR adds a pure-Python implementation of the A (A-star) pathfinding algorithm that works over arbitrary graphs via a neighbors(node) callback and an admissible heuristic h(node, goal). The module includes comprehensive docstrings, type hints, and doctests showing usage on a 4-connected grid with Manhattan distance. The implementation tracks g (cost-so-far), uses a min-heap priority queue for f = g + h, and reconstructs the optimal path via a parent map.*
File added
searches/astar.py (all lowercase, no spaces or dashes)
Complexity
Reference
A* search algorithm — (Wikipedia)
Manhattan distance (Taxicab geometry)
Describe your change:
Checklist: