976 lines
40 KiB
Python
976 lines
40 KiB
Python
"""
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Code to support various backends in a plugin dispatch architecture.
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Create a Dispatcher
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-------------------
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To be a valid backend, a package must register an entry_point
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of `networkx.backends` with a key pointing to the handler.
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For example::
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entry_points={'networkx.backends': 'sparse = networkx_backend_sparse'}
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The backend must create a Graph-like object which contains an attribute
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``__networkx_backend__`` with a value of the entry point name.
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Continuing the example above::
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class WrappedSparse:
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__networkx_backend__ = "sparse"
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...
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When a dispatchable NetworkX algorithm encounters a Graph-like object
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with a ``__networkx_backend__`` attribute, it will look for the associated
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dispatch object in the entry_points, load it, and dispatch the work to it.
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Testing
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-------
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To assist in validating the backend algorithm implementations, if an
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environment variable ``NETWORKX_TEST_BACKEND`` is set to a registered
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backend key, the dispatch machinery will automatically convert regular
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networkx Graphs and DiGraphs to the backend equivalent by calling
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``<backend dispatcher>.convert_from_nx(G, edge_attrs=edge_attrs, name=name)``.
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Set ``NETWORKX_FALLBACK_TO_NX`` environment variable to have tests
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use networkx graphs for algorithms not implemented by the backend.
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The arguments to ``convert_from_nx`` are:
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- ``G`` : networkx Graph
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- ``edge_attrs`` : dict, optional
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Dict that maps edge attributes to default values if missing in ``G``.
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If None, then no edge attributes will be converted and default may be 1.
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- ``node_attrs``: dict, optional
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Dict that maps node attribute to default values if missing in ``G``.
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If None, then no node attributes will be converted.
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- ``preserve_edge_attrs`` : bool
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Whether to preserve all edge attributes.
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- ``preserve_node_attrs`` : bool
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Whether to preserve all node attributes.
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- ``preserve_graph_attrs`` : bool
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Whether to preserve all graph attributes.
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- ``preserve_all_attrs`` : bool
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Whether to preserve all graph, node, and edge attributes.
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- ``name`` : str
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The name of the algorithm.
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- ``graph_name`` : str
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The name of the graph argument being converted.
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The converted object is then passed to the backend implementation of
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the algorithm. The result is then passed to
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``<backend dispatcher>.convert_to_nx(result, name=name)`` to convert back
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to a form expected by the NetworkX tests.
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By defining ``convert_from_nx`` and ``convert_to_nx`` methods and setting
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the environment variable, NetworkX will automatically route tests on
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dispatchable algorithms to the backend, allowing the full networkx test
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suite to be run against the backend implementation.
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Example pytest invocation::
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NETWORKX_TEST_BACKEND=sparse pytest --pyargs networkx
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Dispatchable algorithms which are not implemented by the backend
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will cause a ``pytest.xfail()``, giving some indication that not all
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tests are working, while avoiding causing an explicit failure.
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If a backend only partially implements some algorithms, it can define
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a ``can_run(name, args, kwargs)`` function that returns True or False
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indicating whether it can run the algorithm with the given arguments.
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A special ``on_start_tests(items)`` function may be defined by the backend.
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It will be called with the list of NetworkX tests discovered. Each item
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is a test object that can be marked as xfail if the backend does not support
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the test using `item.add_marker(pytest.mark.xfail(reason=...))`.
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"""
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import inspect
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import os
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import sys
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import warnings
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from functools import partial
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from importlib.metadata import entry_points
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from ..exception import NetworkXNotImplemented
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__all__ = ["_dispatch"]
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def _get_backends(group, *, load_and_call=False):
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if sys.version_info < (3, 10):
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eps = entry_points()
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if group not in eps:
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return {}
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items = eps[group]
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else:
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items = entry_points(group=group)
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rv = {}
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for ep in items:
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if ep.name in rv:
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warnings.warn(
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f"networkx backend defined more than once: {ep.name}",
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RuntimeWarning,
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stacklevel=2,
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)
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elif load_and_call:
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try:
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rv[ep.name] = ep.load()()
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except Exception as exc:
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warnings.warn(
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f"Error encountered when loading info for backend {ep.name}: {exc}",
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RuntimeWarning,
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stacklevel=2,
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)
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else:
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rv[ep.name] = ep
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# nx-loopback backend is only available when testing (added in conftest.py)
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rv.pop("nx-loopback", None)
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return rv
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# Rename "plugin" to "backend", and give backends a release cycle to update.
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backends = _get_backends("networkx.plugins")
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backend_info = _get_backends("networkx.plugin_info", load_and_call=True)
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backends.update(_get_backends("networkx.backends"))
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backend_info.update(_get_backends("networkx.backend_info", load_and_call=True))
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# Load and cache backends on-demand
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_loaded_backends = {} # type: ignore[var-annotated]
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def _load_backend(backend_name):
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if backend_name in _loaded_backends:
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return _loaded_backends[backend_name]
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rv = _loaded_backends[backend_name] = backends[backend_name].load()
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return rv
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_registered_algorithms = {}
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class _dispatch:
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"""Dispatches to a backend algorithm based on input graph types.
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Parameters
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----------
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func : function
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name : str, optional
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The name of the algorithm to use for dispatching. If not provided,
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the name of ``func`` will be used. ``name`` is useful to avoid name
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conflicts, as all dispatched algorithms live in a single namespace.
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graphs : str or dict or None, default "G"
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If a string, the parameter name of the graph, which must be the first
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argument of the wrapped function. If more than one graph is required
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for the algorithm (or if the graph is not the first argument), provide
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a dict of parameter name to argument position for each graph argument.
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For example, ``@_dispatch(graphs={"G": 0, "auxiliary?": 4})``
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indicates the 0th parameter ``G`` of the function is a required graph,
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and the 4th parameter ``auxiliary`` is an optional graph.
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To indicate an argument is a list of graphs, do e.g. ``"[graphs]"``.
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Use ``graphs=None`` if *no* arguments are NetworkX graphs such as for
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graph generators, readers, and conversion functions.
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edge_attrs : str or dict, optional
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``edge_attrs`` holds information about edge attribute arguments
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and default values for those edge attributes.
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If a string, ``edge_attrs`` holds the function argument name that
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indicates a single edge attribute to include in the converted graph.
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The default value for this attribute is 1. To indicate that an argument
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is a list of attributes (all with default value 1), use e.g. ``"[attrs]"``.
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If a dict, ``edge_attrs`` holds a dict keyed by argument names, with
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values that are either the default value or, if a string, the argument
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name that indicates the default value.
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node_attrs : str or dict, optional
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Like ``edge_attrs``, but for node attributes.
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preserve_edge_attrs : bool or str or dict, optional
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For bool, whether to preserve all edge attributes.
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For str, the parameter name that may indicate (with ``True`` or a
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callable argument) whether all edge attributes should be preserved
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when converting.
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For dict of ``{graph_name: {attr: default}}``, indicate pre-determined
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edge attributes (and defaults) to preserve for input graphs.
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preserve_node_attrs : bool or str or dict, optional
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Like ``preserve_edge_attrs``, but for node attributes.
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preserve_graph_attrs : bool or set
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For bool, whether to preserve all graph attributes.
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For set, which input graph arguments to preserve graph attributes.
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preserve_all_attrs : bool
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Whether to preserve all edge, node and graph attributes.
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This overrides all the other preserve_*_attrs.
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"""
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# Allow any of the following decorator forms:
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# - @_dispatch
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# - @_dispatch()
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# - @_dispatch(name="override_name")
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# - @_dispatch(graphs="graph")
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# - @_dispatch(edge_attrs="weight")
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# - @_dispatch(graphs={"G": 0, "H": 1}, edge_attrs={"weight": "default"})
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# These class attributes are currently used to allow backends to run networkx tests.
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# For example: `PYTHONPATH=. pytest --backend graphblas --fallback-to-nx`
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# Future work: add configuration to control these
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_is_testing = False
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_fallback_to_nx = (
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os.environ.get("NETWORKX_FALLBACK_TO_NX", "true").strip().lower() == "true"
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)
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_automatic_backends = [
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x.strip()
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for x in os.environ.get("NETWORKX_AUTOMATIC_BACKENDS", "").split(",")
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if x.strip()
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]
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def __new__(
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cls,
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func=None,
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*,
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name=None,
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graphs="G",
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edge_attrs=None,
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node_attrs=None,
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preserve_edge_attrs=False,
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preserve_node_attrs=False,
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preserve_graph_attrs=False,
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preserve_all_attrs=False,
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):
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if func is None:
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return partial(
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_dispatch,
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name=name,
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graphs=graphs,
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edge_attrs=edge_attrs,
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node_attrs=node_attrs,
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preserve_edge_attrs=preserve_edge_attrs,
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preserve_node_attrs=preserve_node_attrs,
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preserve_graph_attrs=preserve_graph_attrs,
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preserve_all_attrs=preserve_all_attrs,
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)
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if isinstance(func, str):
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raise TypeError("'name' and 'graphs' must be passed by keyword") from None
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# If name not provided, use the name of the function
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if name is None:
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name = func.__name__
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self = object.__new__(cls)
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# standard function-wrapping stuff
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# __annotations__ not used
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self.__name__ = func.__name__
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# self.__doc__ = func.__doc__ # __doc__ handled as cached property
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self.__defaults__ = func.__defaults__
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# We "magically" add `backend=` keyword argument to allow backend to be specified
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if func.__kwdefaults__:
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self.__kwdefaults__ = {**func.__kwdefaults__, "backend": None}
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else:
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self.__kwdefaults__ = {"backend": None}
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self.__module__ = func.__module__
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self.__qualname__ = func.__qualname__
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self.__dict__.update(func.__dict__)
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self.__wrapped__ = func
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# Supplement docstring with backend info; compute and cache when needed
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self._orig_doc = func.__doc__
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self._cached_doc = None
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self.orig_func = func
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self.name = name
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self.edge_attrs = edge_attrs
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self.node_attrs = node_attrs
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self.preserve_edge_attrs = preserve_edge_attrs or preserve_all_attrs
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self.preserve_node_attrs = preserve_node_attrs or preserve_all_attrs
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self.preserve_graph_attrs = preserve_graph_attrs or preserve_all_attrs
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if edge_attrs is not None and not isinstance(edge_attrs, (str, dict)):
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raise TypeError(
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f"Bad type for edge_attrs: {type(edge_attrs)}. Expected str or dict."
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) from None
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if node_attrs is not None and not isinstance(node_attrs, (str, dict)):
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raise TypeError(
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f"Bad type for node_attrs: {type(node_attrs)}. Expected str or dict."
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) from None
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if not isinstance(self.preserve_edge_attrs, (bool, str, dict)):
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raise TypeError(
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f"Bad type for preserve_edge_attrs: {type(self.preserve_edge_attrs)}."
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" Expected bool, str, or dict."
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) from None
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if not isinstance(self.preserve_node_attrs, (bool, str, dict)):
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raise TypeError(
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f"Bad type for preserve_node_attrs: {type(self.preserve_node_attrs)}."
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" Expected bool, str, or dict."
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) from None
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if not isinstance(self.preserve_graph_attrs, (bool, set)):
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raise TypeError(
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f"Bad type for preserve_graph_attrs: {type(self.preserve_graph_attrs)}."
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" Expected bool or set."
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) from None
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if isinstance(graphs, str):
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graphs = {graphs: 0}
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elif graphs is None:
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pass
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elif not isinstance(graphs, dict):
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raise TypeError(
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f"Bad type for graphs: {type(graphs)}. Expected str or dict."
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) from None
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elif len(graphs) == 0:
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raise KeyError("'graphs' must contain at least one variable name") from None
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# This dict comprehension is complicated for better performance; equivalent shown below.
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self.optional_graphs = set()
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self.list_graphs = set()
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if graphs is None:
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self.graphs = {}
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else:
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self.graphs = {
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self.optional_graphs.add(val := k[:-1]) or val
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if (last := k[-1]) == "?"
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else self.list_graphs.add(val := k[1:-1]) or val
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if last == "]"
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else k: v
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for k, v in graphs.items()
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}
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# The above is equivalent to:
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# self.optional_graphs = {k[:-1] for k in graphs if k[-1] == "?"}
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# self.list_graphs = {k[1:-1] for k in graphs if k[-1] == "]"}
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# self.graphs = {k[:-1] if k[-1] == "?" else k: v for k, v in graphs.items()}
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# Compute and cache the signature on-demand
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self._sig = None
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# Which backends implement this function?
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self.backends = {
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backend
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for backend, info in backend_info.items()
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if "functions" in info and name in info["functions"]
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}
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if name in _registered_algorithms:
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raise KeyError(
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f"Algorithm already exists in dispatch registry: {name}"
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) from None
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_registered_algorithms[name] = self
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return self
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@property
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def __doc__(self):
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if (rv := self._cached_doc) is not None:
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return rv
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rv = self._cached_doc = self._make_doc()
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return rv
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@__doc__.setter
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def __doc__(self, val):
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self._orig_doc = val
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self._cached_doc = None
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@property
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def __signature__(self):
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if self._sig is None:
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sig = inspect.signature(self.orig_func)
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# `backend` is now a reserved argument used by dispatching.
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# assert "backend" not in sig.parameters
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if not any(
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p.kind == inspect.Parameter.VAR_KEYWORD for p in sig.parameters.values()
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):
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sig = sig.replace(
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parameters=[
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*sig.parameters.values(),
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inspect.Parameter(
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"backend", inspect.Parameter.KEYWORD_ONLY, default=None
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),
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inspect.Parameter(
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"backend_kwargs", inspect.Parameter.VAR_KEYWORD
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),
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]
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)
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else:
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*parameters, var_keyword = sig.parameters.values()
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sig = sig.replace(
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parameters=[
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*parameters,
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inspect.Parameter(
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"backend", inspect.Parameter.KEYWORD_ONLY, default=None
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),
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var_keyword,
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]
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)
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self._sig = sig
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return self._sig
|
|
|
|
def __call__(self, /, *args, backend=None, **kwargs):
|
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if not backends:
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# Fast path if no backends are installed
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return self.orig_func(*args, **kwargs)
|
|
|
|
# Use `backend_name` in this function instead of `backend`
|
|
backend_name = backend
|
|
if backend_name is not None and backend_name not in backends:
|
|
raise ImportError(f"Unable to load backend: {backend_name}")
|
|
|
|
graphs_resolved = {}
|
|
for gname, pos in self.graphs.items():
|
|
if pos < len(args):
|
|
if gname in kwargs:
|
|
raise TypeError(f"{self.name}() got multiple values for {gname!r}")
|
|
val = args[pos]
|
|
elif gname in kwargs:
|
|
val = kwargs[gname]
|
|
elif gname not in self.optional_graphs:
|
|
raise TypeError(
|
|
f"{self.name}() missing required graph argument: {gname}"
|
|
)
|
|
else:
|
|
continue
|
|
if val is None:
|
|
if gname not in self.optional_graphs:
|
|
raise TypeError(
|
|
f"{self.name}() required graph argument {gname!r} is None; must be a graph"
|
|
)
|
|
else:
|
|
graphs_resolved[gname] = val
|
|
|
|
# Alternative to the above that does not check duplicated args or missing required graphs.
|
|
# graphs_resolved = {
|
|
# val
|
|
# for gname, pos in self.graphs.items()
|
|
# if (val := args[pos] if pos < len(args) else kwargs.get(gname)) is not None
|
|
# }
|
|
|
|
if self._is_testing and self._automatic_backends and backend_name is None:
|
|
# Special path if we are running networkx tests with a backend.
|
|
return self._convert_and_call_for_tests(
|
|
self._automatic_backends[0],
|
|
args,
|
|
kwargs,
|
|
fallback_to_nx=self._fallback_to_nx,
|
|
)
|
|
|
|
# Check if any graph comes from a backend
|
|
if self.list_graphs:
|
|
# Make sure we don't lose values by consuming an iterator
|
|
args = list(args)
|
|
for gname in self.list_graphs & graphs_resolved.keys():
|
|
val = list(graphs_resolved[gname])
|
|
graphs_resolved[gname] = val
|
|
if gname in kwargs:
|
|
kwargs[gname] = val
|
|
else:
|
|
args[self.graphs[gname]] = val
|
|
|
|
has_backends = any(
|
|
hasattr(g, "__networkx_backend__") or hasattr(g, "__networkx_plugin__")
|
|
if gname not in self.list_graphs
|
|
else any(
|
|
hasattr(g2, "__networkx_backend__")
|
|
or hasattr(g2, "__networkx_plugin__")
|
|
for g2 in g
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|
)
|
|
for gname, g in graphs_resolved.items()
|
|
)
|
|
if has_backends:
|
|
graph_backend_names = {
|
|
getattr(
|
|
g,
|
|
"__networkx_backend__",
|
|
getattr(g, "__networkx_plugin__", "networkx"),
|
|
)
|
|
for gname, g in graphs_resolved.items()
|
|
if gname not in self.list_graphs
|
|
}
|
|
for gname in self.list_graphs & graphs_resolved.keys():
|
|
graph_backend_names.update(
|
|
getattr(
|
|
g,
|
|
"__networkx_backend__",
|
|
getattr(g, "__networkx_plugin__", "networkx"),
|
|
)
|
|
for g in graphs_resolved[gname]
|
|
)
|
|
else:
|
|
has_backends = any(
|
|
hasattr(g, "__networkx_backend__") or hasattr(g, "__networkx_plugin__")
|
|
for g in graphs_resolved.values()
|
|
)
|
|
if has_backends:
|
|
graph_backend_names = {
|
|
getattr(
|
|
g,
|
|
"__networkx_backend__",
|
|
getattr(g, "__networkx_plugin__", "networkx"),
|
|
)
|
|
for g in graphs_resolved.values()
|
|
}
|
|
if has_backends:
|
|
# Dispatchable graphs found! Dispatch to backend function.
|
|
# We don't handle calls with different backend graphs yet,
|
|
# but we may be able to convert additional networkx graphs.
|
|
backend_names = graph_backend_names - {"networkx"}
|
|
if len(backend_names) != 1:
|
|
# Future work: convert between backends and run if multiple backends found
|
|
raise TypeError(
|
|
f"{self.name}() graphs must all be from the same backend, found {backend_names}"
|
|
)
|
|
[graph_backend_name] = backend_names
|
|
if backend_name is not None and backend_name != graph_backend_name:
|
|
# Future work: convert between backends to `backend_name` backend
|
|
raise TypeError(
|
|
f"{self.name}() is unable to convert graph from backend {graph_backend_name!r} "
|
|
f"to the specified backend {backend_name!r}."
|
|
)
|
|
if graph_backend_name not in backends:
|
|
raise ImportError(f"Unable to load backend: {graph_backend_name}")
|
|
if (
|
|
"networkx" in graph_backend_names
|
|
and graph_backend_name not in self._automatic_backends
|
|
):
|
|
# Not configured to convert networkx graphs to this backend
|
|
raise TypeError(
|
|
f"Unable to convert inputs and run {self.name}. "
|
|
f"{self.name}() has networkx and {graph_backend_name} graphs, but NetworkX is not "
|
|
f"configured to automatically convert graphs from networkx to {graph_backend_name}."
|
|
)
|
|
backend = _load_backend(graph_backend_name)
|
|
if hasattr(backend, self.name):
|
|
if "networkx" in graph_backend_names:
|
|
# We need to convert networkx graphs to backend graphs
|
|
return self._convert_and_call(
|
|
graph_backend_name,
|
|
args,
|
|
kwargs,
|
|
fallback_to_nx=self._fallback_to_nx,
|
|
)
|
|
# All graphs are backend graphs--no need to convert!
|
|
return getattr(backend, self.name)(*args, **kwargs)
|
|
# Future work: try to convert and run with other backends in self._automatic_backends
|
|
raise NetworkXNotImplemented(
|
|
f"'{self.name}' not implemented by {graph_backend_name}"
|
|
)
|
|
|
|
# If backend was explicitly given by the user, so we need to use it no matter what
|
|
if backend_name is not None:
|
|
return self._convert_and_call(
|
|
backend_name, args, kwargs, fallback_to_nx=False
|
|
)
|
|
|
|
# Only networkx graphs; try to convert and run with a backend with automatic
|
|
# conversion, but don't do this by default for graph generators or loaders.
|
|
if self.graphs:
|
|
for backend_name in self._automatic_backends:
|
|
if self._can_backend_run(backend_name, *args, **kwargs):
|
|
return self._convert_and_call(
|
|
backend_name,
|
|
args,
|
|
kwargs,
|
|
fallback_to_nx=self._fallback_to_nx,
|
|
)
|
|
# Default: run with networkx on networkx inputs
|
|
return self.orig_func(*args, **kwargs)
|
|
|
|
def _can_backend_run(self, backend_name, /, *args, **kwargs):
|
|
"""Can the specified backend run this algorithms with these arguments?"""
|
|
backend = _load_backend(backend_name)
|
|
return hasattr(backend, self.name) and (
|
|
not hasattr(backend, "can_run") or backend.can_run(self.name, args, kwargs)
|
|
)
|
|
|
|
def _convert_arguments(self, backend_name, args, kwargs):
|
|
"""Convert graph arguments to the specified backend.
|
|
|
|
Returns
|
|
-------
|
|
args tuple and kwargs dict
|
|
"""
|
|
bound = self.__signature__.bind(*args, **kwargs)
|
|
bound.apply_defaults()
|
|
if not self.graphs:
|
|
bound_kwargs = bound.kwargs
|
|
del bound_kwargs["backend"]
|
|
return bound.args, bound_kwargs
|
|
# Convert graphs into backend graph-like object
|
|
# Include the edge and/or node labels if provided to the algorithm
|
|
preserve_edge_attrs = self.preserve_edge_attrs
|
|
edge_attrs = self.edge_attrs
|
|
if preserve_edge_attrs is False:
|
|
# e.g. `preserve_edge_attrs=False`
|
|
pass
|
|
elif preserve_edge_attrs is True:
|
|
# e.g. `preserve_edge_attrs=True`
|
|
edge_attrs = None
|
|
elif isinstance(preserve_edge_attrs, str):
|
|
if bound.arguments[preserve_edge_attrs] is True or callable(
|
|
bound.arguments[preserve_edge_attrs]
|
|
):
|
|
# e.g. `preserve_edge_attrs="attr"` and `func(attr=True)`
|
|
# e.g. `preserve_edge_attrs="attr"` and `func(attr=myfunc)`
|
|
preserve_edge_attrs = True
|
|
edge_attrs = None
|
|
elif bound.arguments[preserve_edge_attrs] is False and (
|
|
isinstance(edge_attrs, str)
|
|
and edge_attrs == preserve_edge_attrs
|
|
or isinstance(edge_attrs, dict)
|
|
and preserve_edge_attrs in edge_attrs
|
|
):
|
|
# e.g. `preserve_edge_attrs="attr"` and `func(attr=False)`
|
|
# Treat `False` argument as meaning "preserve_edge_data=False"
|
|
# and not `False` as the edge attribute to use.
|
|
preserve_edge_attrs = False
|
|
edge_attrs = None
|
|
else:
|
|
# e.g. `preserve_edge_attrs="attr"` and `func(attr="weight")`
|
|
preserve_edge_attrs = False
|
|
# Else: e.g. `preserve_edge_attrs={"G": {"weight": 1}}`
|
|
|
|
if edge_attrs is None:
|
|
# May have been set to None above b/c all attributes are preserved
|
|
pass
|
|
elif isinstance(edge_attrs, str):
|
|
if edge_attrs[0] == "[":
|
|
# e.g. `edge_attrs="[edge_attributes]"` (argument of list of attributes)
|
|
# e.g. `func(edge_attributes=["foo", "bar"])`
|
|
edge_attrs = {
|
|
edge_attr: 1 for edge_attr in bound.arguments[edge_attrs[1:-1]]
|
|
}
|
|
elif callable(bound.arguments[edge_attrs]):
|
|
# e.g. `edge_attrs="weight"` and `func(weight=myfunc)`
|
|
preserve_edge_attrs = True
|
|
edge_attrs = None
|
|
elif bound.arguments[edge_attrs] is not None:
|
|
# e.g. `edge_attrs="weight"` and `func(weight="foo")` (default of 1)
|
|
edge_attrs = {bound.arguments[edge_attrs]: 1}
|
|
elif self.name == "to_numpy_array" and hasattr(
|
|
bound.arguments["dtype"], "names"
|
|
):
|
|
# Custom handling: attributes may be obtained from `dtype`
|
|
edge_attrs = {
|
|
edge_attr: 1 for edge_attr in bound.arguments["dtype"].names
|
|
}
|
|
else:
|
|
# e.g. `edge_attrs="weight"` and `func(weight=None)`
|
|
edge_attrs = None
|
|
else:
|
|
# e.g. `edge_attrs={"attr": "default"}` and `func(attr="foo", default=7)`
|
|
# e.g. `edge_attrs={"attr": 0}` and `func(attr="foo")`
|
|
edge_attrs = {
|
|
edge_attr: bound.arguments.get(val, 1) if isinstance(val, str) else val
|
|
for key, val in edge_attrs.items()
|
|
if (edge_attr := bound.arguments[key]) is not None
|
|
}
|
|
|
|
preserve_node_attrs = self.preserve_node_attrs
|
|
node_attrs = self.node_attrs
|
|
if preserve_node_attrs is False:
|
|
# e.g. `preserve_node_attrs=False`
|
|
pass
|
|
elif preserve_node_attrs is True:
|
|
# e.g. `preserve_node_attrs=True`
|
|
node_attrs = None
|
|
elif isinstance(preserve_node_attrs, str):
|
|
if bound.arguments[preserve_node_attrs] is True or callable(
|
|
bound.arguments[preserve_node_attrs]
|
|
):
|
|
# e.g. `preserve_node_attrs="attr"` and `func(attr=True)`
|
|
# e.g. `preserve_node_attrs="attr"` and `func(attr=myfunc)`
|
|
preserve_node_attrs = True
|
|
node_attrs = None
|
|
elif bound.arguments[preserve_node_attrs] is False and (
|
|
isinstance(node_attrs, str)
|
|
and node_attrs == preserve_node_attrs
|
|
or isinstance(node_attrs, dict)
|
|
and preserve_node_attrs in node_attrs
|
|
):
|
|
# e.g. `preserve_node_attrs="attr"` and `func(attr=False)`
|
|
# Treat `False` argument as meaning "preserve_node_data=False"
|
|
# and not `False` as the node attribute to use. Is this used?
|
|
preserve_node_attrs = False
|
|
node_attrs = None
|
|
else:
|
|
# e.g. `preserve_node_attrs="attr"` and `func(attr="weight")`
|
|
preserve_node_attrs = False
|
|
# Else: e.g. `preserve_node_attrs={"G": {"pos": None}}`
|
|
|
|
if node_attrs is None:
|
|
# May have been set to None above b/c all attributes are preserved
|
|
pass
|
|
elif isinstance(node_attrs, str):
|
|
if node_attrs[0] == "[":
|
|
# e.g. `node_attrs="[node_attributes]"` (argument of list of attributes)
|
|
# e.g. `func(node_attributes=["foo", "bar"])`
|
|
node_attrs = {
|
|
node_attr: None for node_attr in bound.arguments[node_attrs[1:-1]]
|
|
}
|
|
elif callable(bound.arguments[node_attrs]):
|
|
# e.g. `node_attrs="weight"` and `func(weight=myfunc)`
|
|
preserve_node_attrs = True
|
|
node_attrs = None
|
|
elif bound.arguments[node_attrs] is not None:
|
|
# e.g. `node_attrs="weight"` and `func(weight="foo")`
|
|
node_attrs = {bound.arguments[node_attrs]: None}
|
|
else:
|
|
# e.g. `node_attrs="weight"` and `func(weight=None)`
|
|
node_attrs = None
|
|
else:
|
|
# e.g. `node_attrs={"attr": "default"}` and `func(attr="foo", default=7)`
|
|
# e.g. `node_attrs={"attr": 0}` and `func(attr="foo")`
|
|
node_attrs = {
|
|
node_attr: bound.arguments.get(val) if isinstance(val, str) else val
|
|
for key, val in node_attrs.items()
|
|
if (node_attr := bound.arguments[key]) is not None
|
|
}
|
|
|
|
preserve_graph_attrs = self.preserve_graph_attrs
|
|
|
|
# It should be safe to assume that we either have networkx graphs or backend graphs.
|
|
# Future work: allow conversions between backends.
|
|
backend = _load_backend(backend_name)
|
|
for gname in self.graphs:
|
|
if gname in self.list_graphs:
|
|
bound.arguments[gname] = [
|
|
backend.convert_from_nx(
|
|
g,
|
|
edge_attrs=edge_attrs,
|
|
node_attrs=node_attrs,
|
|
preserve_edge_attrs=preserve_edge_attrs,
|
|
preserve_node_attrs=preserve_node_attrs,
|
|
preserve_graph_attrs=preserve_graph_attrs,
|
|
name=self.name,
|
|
graph_name=gname,
|
|
)
|
|
if getattr(
|
|
g,
|
|
"__networkx_backend__",
|
|
getattr(g, "__networkx_plugin__", "networkx"),
|
|
)
|
|
== "networkx"
|
|
else g
|
|
for g in bound.arguments[gname]
|
|
]
|
|
else:
|
|
graph = bound.arguments[gname]
|
|
if graph is None:
|
|
if gname in self.optional_graphs:
|
|
continue
|
|
raise TypeError(
|
|
f"Missing required graph argument `{gname}` in {self.name} function"
|
|
)
|
|
if isinstance(preserve_edge_attrs, dict):
|
|
preserve_edges = False
|
|
edges = preserve_edge_attrs.get(gname, edge_attrs)
|
|
else:
|
|
preserve_edges = preserve_edge_attrs
|
|
edges = edge_attrs
|
|
if isinstance(preserve_node_attrs, dict):
|
|
preserve_nodes = False
|
|
nodes = preserve_node_attrs.get(gname, node_attrs)
|
|
else:
|
|
preserve_nodes = preserve_node_attrs
|
|
nodes = node_attrs
|
|
if isinstance(preserve_graph_attrs, set):
|
|
preserve_graph = gname in preserve_graph_attrs
|
|
else:
|
|
preserve_graph = preserve_graph_attrs
|
|
if (
|
|
getattr(
|
|
graph,
|
|
"__networkx_backend__",
|
|
getattr(graph, "__networkx_plugin__", "networkx"),
|
|
)
|
|
== "networkx"
|
|
):
|
|
bound.arguments[gname] = backend.convert_from_nx(
|
|
graph,
|
|
edge_attrs=edges,
|
|
node_attrs=nodes,
|
|
preserve_edge_attrs=preserve_edges,
|
|
preserve_node_attrs=preserve_nodes,
|
|
preserve_graph_attrs=preserve_graph,
|
|
name=self.name,
|
|
graph_name=gname,
|
|
)
|
|
bound_kwargs = bound.kwargs
|
|
del bound_kwargs["backend"]
|
|
return bound.args, bound_kwargs
|
|
|
|
def _convert_and_call(self, backend_name, args, kwargs, *, fallback_to_nx=False):
|
|
"""Call this dispatchable function with a backend, converting graphs if necessary."""
|
|
backend = _load_backend(backend_name)
|
|
if not self._can_backend_run(backend_name, *args, **kwargs):
|
|
if fallback_to_nx:
|
|
return self.orig_func(*args, **kwargs)
|
|
msg = f"'{self.name}' not implemented by {backend_name}"
|
|
if hasattr(backend, self.name):
|
|
msg += " with the given arguments"
|
|
raise RuntimeError(msg)
|
|
|
|
try:
|
|
converted_args, converted_kwargs = self._convert_arguments(
|
|
backend_name, args, kwargs
|
|
)
|
|
result = getattr(backend, self.name)(*converted_args, **converted_kwargs)
|
|
except (NotImplementedError, NetworkXNotImplemented) as exc:
|
|
if fallback_to_nx:
|
|
return self.orig_func(*args, **kwargs)
|
|
raise
|
|
|
|
return result
|
|
|
|
def _convert_and_call_for_tests(
|
|
self, backend_name, args, kwargs, *, fallback_to_nx=False
|
|
):
|
|
"""Call this dispatchable function with a backend; for use with testing."""
|
|
backend = _load_backend(backend_name)
|
|
if not self._can_backend_run(backend_name, *args, **kwargs):
|
|
if fallback_to_nx or not self.graphs:
|
|
return self.orig_func(*args, **kwargs)
|
|
|
|
import pytest
|
|
|
|
msg = f"'{self.name}' not implemented by {backend_name}"
|
|
if hasattr(backend, self.name):
|
|
msg += " with the given arguments"
|
|
pytest.xfail(msg)
|
|
|
|
try:
|
|
converted_args, converted_kwargs = self._convert_arguments(
|
|
backend_name, args, kwargs
|
|
)
|
|
result = getattr(backend, self.name)(*converted_args, **converted_kwargs)
|
|
except (NotImplementedError, NetworkXNotImplemented) as exc:
|
|
if fallback_to_nx:
|
|
return self.orig_func(*args, **kwargs)
|
|
import pytest
|
|
|
|
pytest.xfail(
|
|
exc.args[0] if exc.args else f"{self.name} raised {type(exc).__name__}"
|
|
)
|
|
|
|
if self.name in {
|
|
"edmonds_karp_core",
|
|
"barycenter",
|
|
"contracted_nodes",
|
|
"stochastic_graph",
|
|
"relabel_nodes",
|
|
}:
|
|
# Special-case algorithms that mutate input graphs
|
|
bound = self.__signature__.bind(*converted_args, **converted_kwargs)
|
|
bound.apply_defaults()
|
|
bound2 = self.__signature__.bind(*args, **kwargs)
|
|
bound2.apply_defaults()
|
|
if self.name == "edmonds_karp_core":
|
|
R1 = backend.convert_to_nx(bound.arguments["R"])
|
|
R2 = bound2.arguments["R"]
|
|
for k, v in R1.edges.items():
|
|
R2.edges[k]["flow"] = v["flow"]
|
|
elif self.name == "barycenter" and bound.arguments["attr"] is not None:
|
|
G1 = backend.convert_to_nx(bound.arguments["G"])
|
|
G2 = bound2.arguments["G"]
|
|
attr = bound.arguments["attr"]
|
|
for k, v in G1.nodes.items():
|
|
G2.nodes[k][attr] = v[attr]
|
|
elif self.name == "contracted_nodes" and not bound.arguments["copy"]:
|
|
# Edges and nodes changed; node "contraction" and edge "weight" attrs
|
|
G1 = backend.convert_to_nx(bound.arguments["G"])
|
|
G2 = bound2.arguments["G"]
|
|
G2.__dict__.update(G1.__dict__)
|
|
elif self.name == "stochastic_graph" and not bound.arguments["copy"]:
|
|
G1 = backend.convert_to_nx(bound.arguments["G"])
|
|
G2 = bound2.arguments["G"]
|
|
for k, v in G1.edges.items():
|
|
G2.edges[k]["weight"] = v["weight"]
|
|
elif self.name == "relabel_nodes" and not bound.arguments["copy"]:
|
|
G1 = backend.convert_to_nx(bound.arguments["G"])
|
|
G2 = bound2.arguments["G"]
|
|
if G1 is G2:
|
|
return G2
|
|
G2._node.clear()
|
|
G2._node.update(G1._node)
|
|
G2._adj.clear()
|
|
G2._adj.update(G1._adj)
|
|
if hasattr(G1, "_pred") and hasattr(G2, "_pred"):
|
|
G2._pred.clear()
|
|
G2._pred.update(G1._pred)
|
|
if hasattr(G1, "_succ") and hasattr(G2, "_succ"):
|
|
G2._succ.clear()
|
|
G2._succ.update(G1._succ)
|
|
return G2
|
|
|
|
return backend.convert_to_nx(result, name=self.name)
|
|
|
|
def _make_doc(self):
|
|
if not self.backends:
|
|
return self._orig_doc
|
|
lines = [
|
|
"Backends",
|
|
"--------",
|
|
]
|
|
for backend in sorted(self.backends):
|
|
info = backend_info[backend]
|
|
if "short_summary" in info:
|
|
lines.append(f"{backend} : {info['short_summary']}")
|
|
else:
|
|
lines.append(backend)
|
|
if "functions" not in info or self.name not in info["functions"]:
|
|
lines.append("")
|
|
continue
|
|
|
|
func_info = info["functions"][self.name]
|
|
if "extra_docstring" in func_info:
|
|
lines.extend(
|
|
f" {line}" if line else line
|
|
for line in func_info["extra_docstring"].split("\n")
|
|
)
|
|
add_gap = True
|
|
else:
|
|
add_gap = False
|
|
if "extra_parameters" in func_info:
|
|
if add_gap:
|
|
lines.append("")
|
|
lines.append(" Extra parameters:")
|
|
extra_parameters = func_info["extra_parameters"]
|
|
for param in sorted(extra_parameters):
|
|
lines.append(f" {param}")
|
|
if desc := extra_parameters[param]:
|
|
lines.append(f" {desc}")
|
|
lines.append("")
|
|
else:
|
|
lines.append("")
|
|
|
|
lines.pop() # Remove last empty line
|
|
to_add = "\n ".join(lines)
|
|
return f"{self._orig_doc.rstrip()}\n\n {to_add}"
|
|
|
|
def __reduce__(self):
|
|
"""Allow this object to be serialized with pickle.
|
|
|
|
This uses the global registry `_registered_algorithms` to deserialize.
|
|
"""
|
|
return _restore_dispatch, (self.name,)
|
|
|
|
|
|
def _restore_dispatch(name):
|
|
return _registered_algorithms[name]
|
|
|
|
|
|
if os.environ.get("_NETWORKX_BUILDING_DOCS_"):
|
|
# When building docs with Sphinx, use the original function with the
|
|
# dispatched __doc__, b/c Sphinx renders normal Python functions better.
|
|
# This doesn't show e.g. `*, backend=None, **backend_kwargs` in the
|
|
# signatures, which is probably okay. It does allow the docstring to be
|
|
# updated based on the installed backends.
|
|
_orig_dispatch = _dispatch
|
|
|
|
def _dispatch(func=None, **kwargs): # type: ignore[no-redef]
|
|
if func is None:
|
|
return partial(_dispatch, **kwargs)
|
|
dispatched_func = _orig_dispatch(func, **kwargs)
|
|
func.__doc__ = dispatched_func.__doc__
|
|
return func
|