add skeleton

.gitignore

@@ -0,0 +1,130 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+pip-wheel-metadata/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+.python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+#Pipfile.lock
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+

README.md

@@ -1 +1,26 @@
-# nx_parallel
+NX-Parallel
+-----------
+
+A NetworkX backend plugin which uses dask for parallelization.
+
+``` python
+In [1]: import networkx as nx; import nx_parallel
+
+In [2]: G = nx.erdos_renyi_graph(10, 0.5)
+
+In [3]: H = nx_parallel.ParallelGraph(G)
+
+In [4]: nx.betweenness_centrality(H)
+Out[4]: 
+{0: 0.0,
+ 1: 0.0,
+ 2: 0.0,
+ 3: 0.0,
+ 4: 0.0,
+ 5: 0.0,
+ 6: 0.0,
+ 7: 0.0,
+ 8: 0.0,
+ 9: 0.0}
+
+```

nx_parallel/__init__.py

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+from .centrality import *
+from .graph import *
+from .interface import *

nx_parallel/centrality.py

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+from joblib import Parallel, delayed
+from networkx.algorithms.centrality.betweenness import (
+    _single_source_shortest_path_basic,
+    _accumulate_endpoints,
+    _accumulate_basic,
+    _rescale,
+    _single_source_dijkstra_path_basic,
+)
+
+__all__ = ["betweenness_centrality"]
+
+
+def betweenness_centrality(
+    G, k=None, normalized=True, weight=None, endpoints=False, seed=None
+):
+    betweenness = dict.fromkeys(G, 0.0)  # b[v]=0 for v in G
+    if k is None:
+        nodes = G
+    else:
+        nodes = seed.sample(list(G.nodes()), k)
+
+    def __node_loop(nodes):
+        for s in nodes:
+            # single source shortest paths
+            if weight is None:  # use BFS
+                S, P, sigma, _ = _single_source_shortest_path_basic(G, s)
+            else:  # use Dijkstra's algorithm
+                S, P, sigma, _ = _single_source_dijkstra_path_basic(G, s, weight)
+            # accumulation
+            if endpoints:
+                betweenness, _ = _accumulate_endpoints(betweenness, S, P, sigma, s)
+            else:
+                betweenness, _ = _accumulate_basic(betweenness, S, P, sigma, s)
+
+    # rescaling
+    betweenness = _rescale(
+        betweenness,
+        len(G),
+        normalized=normalized,
+        directed=G.is_directed(),
+        k=k,
+        endpoints=endpoints,
+    )
+    return betweenness

nx_parallel/graph.py

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+from networkx import Graph
+
+__all__ = ["ParallelGraph"]
+
+
+class ParallelGraph(Graph):
+    __networkx_plugin__ = "parallel"
+
+    def __init__(self, incoming_graph_data=None, **attr):
+        super().__init__(incoming_graph_data, **attr)
+
+    def to_networkx(self):
+        return Graph(self)

nx_parallel/interface.py

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+from .centrality import betweenness_centrality
+
+__all__ = ["Dispatcher"]
+
+
+class Dispatcher:
+    betweenness_centrality = betweenness_centrality
+
+    @staticmethod
+    def convert_from_nx(incoming_graph, weight=None, *, name=None):
+        import networkx as nx
+        from .graph import ParallelGraph
+
+        if isinstance(incoming_graph, nx.Graph):
+            return ParallelGraph(incoming_graph)
+        raise TypeError(f"Unsupported type of graph: {type(incoming_graph)}")
+
+    @staticmethod
+    def convert_to_nx(obj, *, name=None):
+        from .graph import ParallelGraph
+
+        if isinstance(obj, Graph):
+            obj = obj.to_networkx()
+        return obj
+
+    # @staticmethod
+    # def on_start_tests(items):
+    #     try:
+    #         import pytest
+    #     except ImportError:  # pragma: no cover (import)
+    #         return
+    #     skip = [
+    #         ("test_attributes", {"TestBoruvka", "test_mst.py"}),
+    #         ("test_weight_attribute", {"TestBoruvka", "test_mst.py"}),
+    #     ]
+    #     for item in items:
+    #         kset = set(item.keywords)
+    #         for test_name, keywords in skip:
+    #             if item.name == test_name and keywords.issubset(kset):
+    #                 item.add_marker(
+    #                     pytest.mark.xfail(reason="unable to handle multi-attributed graphs")
+    #                 )

pyproject.toml

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+[build-system]
+requires = ["setuptools", "setuptools-scm"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "nx_parallel"
+authors = [
+    {name = "Mridul Seth", email = "mail@mriduls.com"},
+]
+description = "An experimental parallel backend for NetworkX"
+readme = "README.md"
+requires-python = ">=3.10"
+keywords = ["networkx", "algorithms", "parallel"]
+license = {text = "BSD-3-Clause"}
+classifiers = [
+    "Programming Language :: Python :: 3",
+]
+dependencies = [
+    "networkx",
+    "joblib"
+]
+version = '0.0.1'
+
+[project.entry-points."networkx.plugins"]
+parallel = "nx_parallel.interface:Dispatcher"