Fix to #171

benchmarks/benchmarks/bench_core_hypergraph.py

@@ -14,18 +14,15 @@ def setup(self):
 
     def time_edgelist_construction(self):
         xgi.Hypergraph(self.disgene_edgelist)
-    
+
     def time_edgedict_construction(self):
         xgi.Hypergraph(self.disgene_edgedict)
-    
+
     def time_df_construction(self):
         xgi.Hypergraph(self.disgene_df)
 
     def time_node_memberships(self):
-        [
-            self.hypergraph.nodes.memberships(n)
-            for n in self.hypergraph.nodes
-        ]
+        [self.hypergraph.nodes.memberships(n) for n in self.hypergraph.nodes]
 
     def time_edge_members(self):
         [self.hypergraph.edges.members(e) for e in self.hypergraph.edges]
@@ -47,12 +44,12 @@ def time_edge_size(self):
 
     def time_isolates(self):
         self.hypergraph.nodes.isolates()
-    
+
     def time_singletons(self):
         self.hypergraph.edges.singletons()
-    
+
     def time_copy(self):
         self.hypergraph.copy()
-    
+
     def time_dual(self):
-        self.hypergraph.dual()
+        self.hypergraph.dual()

tests/classes/test_hypergraph.py

@@ -131,13 +131,14 @@ def test_hypergraph_attr(edgelist1):
     assert H["color"] == "red"
 
 
-def test_members(edgelist1):
+def test_memberships(edgelist1):
     H = xgi.Hypergraph(edgelist1)
     assert H.nodes.memberships(1) == {0}
     assert H.nodes.memberships(2) == {0}
     assert H.nodes.memberships(3) == {0}
     assert H.nodes.memberships(4) == {1}
     assert H.nodes.memberships(6) == {2, 3}
+    assert H.nodes([1, 2, 6]).memberships() == {1: {0}, 2: {0}, 6: {2, 3}}
     with pytest.raises(IDNotFound):
         H.nodes.memberships(0)
     with pytest.raises(TypeError):

xgi/classes/reportviews.py

@@ -529,14 +529,17 @@ def __init__(self, H, bunch=None):
     def memberships(self, n=None):
         """Get the edge ids of which a node is a member.
 
+        Gets all the node memberships for all nodes in the view if n
+        not specified.
+
         Parameters
         ----------
         n : hashable
             Node ID.
 
         Returns
         -------
-        set
+        dict of sets if n is None, otherwise a set
             Edge memberships.
 
         Raises
@@ -545,7 +548,11 @@ def memberships(self, n=None):
             If `n` is not hashable or if it is not in the hypergraph.
 
         """
-        return self._id_dict.copy() if n is None else self._id_dict[n].copy()
+        return (
+            {key: self._id_dict[key] for key in self}
+            if n is None
+            else self._id_dict[n].copy()
+        )
 
     def isolates(self, ignore_singletons=True):
         """Nodes that belong to no edges.