Merge pull request #53 from OrkoHunter/metis

Put function definitions separate from nxmetis/__init__.py

nxmetis/__init__.py

@@ -17,7 +17,7 @@
 
 from nxmetis import enums
 from nxmetis import exceptions
-from nxmetis import _metis
+from nxmetis import metis
 from nxmetis import types
 
 __all__ = ['node_nested_dissection', 'partition', 'vertex_separator',
@@ -134,7 +134,7 @@ def node_nested_dissection(G, weight='weight', options=None):
     xadj, adjncy = _convert_graph(G)
 
     with _zero_numbering(options):
-        perm = _metis.node_nd(xadj, adjncy, vwgt, options)[0]
+        perm = metis.node_nd(xadj, adjncy, vwgt, options)[0]
 
     nodes = list(G)
     perm = [nodes[i] for i in perm]
@@ -252,7 +252,7 @@ def partition(G, nparts, node_weight='weight', node_size='size',
         tpwgts = list(itertools.chain.from_iterable(tpwgts))
 
     with _zero_numbering(options):
-        objval, part = _metis.part_graph(xadj, adjncy, nparts, vwgt, vsize,
+        objval, part = metis.part_graph(xadj, adjncy, nparts, vwgt, vsize,
                                          adjwgt, tpwgts, ubvec, options,
                                          recursive)
 
@@ -305,7 +305,7 @@ def vertex_separator(G, weight='weight', options=None):
     xadj, adjncy = _convert_graph(G)
 
     with _zero_numbering(options):
-        part = _metis.compute_vertex_separator(xadj, adjncy, vwgt, options)[1]
+        part = metis.compute_vertex_separator(xadj, adjncy, vwgt, options)[1]
 
     groups = [[], [], []]
     for u, i in zip(G, part):

nxmetis/metis.py

@@ -0,0 +1,24 @@
+"""
+    This module is a wrapper of the ``_metis`` extension generated
+    from ``_metis.pyx``. This is to let sphinx import the module for
+    documentation builds with or without the ``_metis`` extension.
+"""
+try:
+    from nxmetis import _metis
+except ImportError:
+    def node_nd(*args, **kwargs):
+        raise Exception("NetworkX-METIS not installed!")
+
+    def part_graph(*args, **kwargs):
+        raise Exception("NetworkX-METIS not installed!")
+
+    def compute_vertex_separator(*args, **kwargs):
+        raise Exception("NetworkX-METIS not installed!")
+
+    def set_default_options(*args, **kwargs):
+        raise Exception("NetworkX-METIS not installed!")
+else:
+    node_nd = _metis.node_nd
+    part_graph = _metis.part_graph
+    compute_vertex_separator = _metis.compute_vertex_separator
+    set_default_options = _metis.set_default_options

nxmetis/tests/test_metis.py

@@ -5,7 +5,7 @@
 
 import nxmetis
 from nxmetis import exceptions
-from nxmetis import _metis
+from nxmetis import metis
 from nxmetis import types
 
 
@@ -102,5 +102,5 @@ def test_MetisOptions(self):
         options = types.MetisOptions(niter=-2)
         nose.tools.assert_raises_regexp(exceptions.MetisError,
                                         'Input Error: Incorrect niter.',
-                                        _metis.part_graph, xadj, adjncy, 2,
+                                        metis.part_graph, xadj, adjncy, 2,
                                         options=options)

nxmetis/types.py

@@ -1,7 +1,7 @@
 import numbers
 
 from nxmetis import enums
-from nxmetis import _metis
+from nxmetis import metis
 
 __all__ = ['MetisOptions']
 
@@ -18,7 +18,7 @@ def __init__(self, **kwargs):
         >>> options = MetisOptions(ncuts=2, niter=100)
 
         """
-        _metis.set_default_options(self)
+        metis.set_default_options(self)
         for key, value in kwargs.items():
             if value is not None:
                 setattr(self, key, value)