complete networkx/...lowest_common_ancestors.pyi

[hunterhogan]

addresses #14499 follows #14509, #14569

added TypeVar for parameter default to class Graph: mirroring class MultiGraph

---

Deferred: Waiting for a stubtest fix: python/mypy#19689

[srittau]

Thanks, a few remarks below.

[hunterhogan]

Veni, vidi, submiti.

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

discord.py (https://github.com/Rapptz/discord.py)
- discord/ext/commands/hybrid.py:508: error: Overlap between argument names and ** TypedDict items: "description", "name"  [misc]
+ discord/ext/commands/hybrid.py:508: error: Overlap between argument names and ** TypedDict items: "name", "description"  [misc]
- discord/ext/commands/hybrid.py:629: error: Overlap between argument names and ** TypedDict items: "description", "name"  [misc]
+ discord/ext/commands/hybrid.py:629: error: Overlap between argument names and ** TypedDict items: "name", "description"  [misc]
- discord/ext/commands/hybrid.py:834: error: Overlap between argument names and ** TypedDict items: "with_app_command", "name"  [misc]
+ discord/ext/commands/hybrid.py:834: error: Overlap between argument names and ** TypedDict items: "name", "with_app_command"  [misc]
- discord/ext/commands/hybrid.py:858: error: Overlap between argument names and ** TypedDict items: "with_app_command", "name"  [misc]
+ discord/ext/commands/hybrid.py:858: error: Overlap between argument names and ** TypedDict items: "name", "with_app_command"  [misc]
- discord/ext/commands/hybrid.py:883: error: Overlap between argument names and ** TypedDict items: "with_app_command", "name"  [misc]
+ discord/ext/commands/hybrid.py:883: error: Overlap between argument names and ** TypedDict items: "name", "with_app_command"  [misc]
- discord/ext/commands/hybrid.py:935: error: Overlap between argument names and ** TypedDict items: "with_app_command", "name"  [misc]
+ discord/ext/commands/hybrid.py:935: error: Overlap between argument names and ** TypedDict items: "name", "with_app_command"  [misc]
- discord/ext/commands/bot.py:291: error: Overlap between argument names and ** TypedDict items: "with_app_command", "name"  [misc]
+ discord/ext/commands/bot.py:291: error: Overlap between argument names and ** TypedDict items: "name", "with_app_command"  [misc]
- discord/ext/commands/bot.py:315: error: Overlap between argument names and ** TypedDict items: "with_app_command", "name"  [misc]
+ discord/ext/commands/bot.py:315: error: Overlap between argument names and ** TypedDict items: "name", "with_app_command"  [misc]

[srittau]

The changes LGTM. I'm a bit baffled why stubtest crashed. This is definitely a bug in stubtest that needs to be investigated. (Even if there was something wrong with the changes, it shouldn't crash, but print a proper error message.)

[brianschubert]

Opened python/mypy#19689 to track the stubtest crash

[srittau]

I've marked this PR as deferred for now until we get a stubtest fix (or a workaround).

[hamdanal]

Note that @overload does not work with @_dispatchable (see #14462 for more information). TLDR, you have to remove the dispatchable decorator if you want to use overloads. Here is a patch that passes stubtest:

diff --git a/stubs/networkx/networkx/algorithms/lowest_common_ancestors.pyi b/stubs/networkx/networkx/algorithms/lowest_common_ancestors.pyi
index 7de4949cc..3244759f3 100644
--- a/stubs/networkx/networkx/algorithms/lowest_common_ancestors.pyi
+++ b/stubs/networkx/networkx/algorithms/lowest_common_ancestors.pyi
@@ -15,11 +15,13 @@ def all_pairs_lowest_common_ancestor(
     G: DiGraph[_Node], pairs: Iterable[tuple[_Node, _Node]] | None = None
 ) -> Generator[tuple[tuple[_Node, _Node], _Node | None]]: ...
 @overload
-@_dispatchable
-def lowest_common_ancestor(G: DiGraph[_Node], node1: _Node, node2: _Node, default: None = None) -> _Node | None: ...
+def lowest_common_ancestor(
+    G: DiGraph[_Node], node1: _Node, node2: _Node, default: None = None, *, backend: str | None = None, **backend_kwargs
+) -> _Node | None: ...
 @overload
-@_dispatchable
-def lowest_common_ancestor(G: DiGraph[_Node], node1: _Node, node2: _Node, default: _DefaultT) -> _Node | _DefaultT: ...
+def lowest_common_ancestor(
+    G: DiGraph[_Node], node1: _Node, node2: _Node, default: _DefaultT, *, backend: str | None = None, **backend_kwargs
+) -> _Node | _DefaultT: ...
 @_dispatchable
 def tree_all_pairs_lowest_common_ancestor(
     G: DiGraph[_Node], root: _Node | None = None, pairs: Iterable[tuple[_Node, _Node]] | None = None

[hunterhogan]

1. Should the stub have @_dispatchable?

I am both ignorant of the answer and apathetic about the question.

2. @srittau wrote, "I'm a bit baffled why stubtest crashed."

I didn't realize stubtest was crashing, even though I saw the error screen at least 20 times. I merely thought stubtest was telling me to fix the stub.

3. @hamdanal wrote, "Note that @overload does not work with @_dispatchable (see #14462 for more information)."

I think that issue is described more generally in

mypy: python/mypy#16840
pyright: microsoft/pyright#7167

typeshed/stubs/networkx/@tests/stubtest_allowlist.txt

Lines 1 to 11 in d270bb0

	# overloaded class-decorators are not properly supported in type-checkers:
	# - mypy: https://github.com/python/mypy/issues/16840
	# - pyright: https://github.com/microsoft/pyright/issues/7167
	networkx\.(algorithms\.)?(boundary\.)?edge_boundary
	networkx\.(algorithms\.)?(bridges\.)?local_bridges
	networkx\.(algorithms\.)?(clique\.)?node_clique_number
	networkx\.(convert_matrix\.)?from_numpy_array
	networkx\.(convert_matrix\.)?from_pandas_adjacency
	networkx\.(convert_matrix\.)?from_pandas_edgelist
	networkx\.(generators\.)?(random_clustered\.)?random_clustered_graph
	networkx\.(relabel\.)?relabel_nodes

I think _dispatchable is a "class-dispatcher", but I've never seen that term before, so I could be wrong.

class _dispatchable:
    _is_testing = False


    def __new__(
...

Therefore, I tried adding

networkx\.(algorithms\.)?(lowest_common_ancestors\.)?lowest_common_ancestor

to https://github.com/python/typeshed/blob/d270bb0dc1df3fcfae2808c9a5a0f7ec802e1fb2/stubs/networkx/%40tests/stubtest_allowlist.txt, but either I didn't do it correctly or it didn't help.

4. Note that "stubtest_allowlist.txt" has a special section just for _dispatchable.

But I couldn't figure out if it was related or how to use the information to resolve the problem.

typeshed/stubs/networkx/@tests/stubtest_allowlist.txt

Lines 24 to 28 in d270bb0

	# Stubtest says: "runtime argument "backend" has a default value of type None, which is
	# incompatible with stub argument type builtins.str. This is often caused by overloads
	# failing to account for explicitly passing in the default value."
	# Which is true, but would require some way of concatenating `backend` to ParamSpec.kwargs
	networkx\.(utils\.)?(backends\.)?_dispatchable\.__call__