diff --git a/tests/test_api_enchance.py b/tests/test_api_enchance.py
index f4e7cc0..18dc91e 100644
--- a/tests/test_api_enchance.py
+++ b/tests/test_api_enchance.py
@@ -74,14 +74,14 @@ def test_remove_edge():
     g.e['color'][4,0] = 1
     g[0,4] = 0
     g[1,0] = 0
-    with pytest.raises(IndexError, match='No such edge'):
+    with pytest.raises(IndexError, match='Missing at least one edge.'):
         g.e['color'][1,4] = 6
-    with pytest.raises(IndexError, match='No such edge.'):
+    with pytest.raises(IndexError, match='Missing at least one edge.'):
         g.e['color'][0,1]
     assert g.e['color'][1,2] == 4
     assert g.e['color'][2,3] == 5
     assert g.e['color'][3,4] == 6
-    with pytest.raises(IndexError, match='No such edge.'):
+    with pytest.raises(IndexError, match='Missing at least one edge.'):
         g.e['color'][4,0]
 
 def test_permute():
@@ -110,4 +110,4 @@ def test_permute():
 
     assert not graph_equality(g2, pG11)
     assert graph_equality(g2, pG12)
-    assert graph_equality(g1, pG13)
\ No newline at end of file
+    assert graph_equality(g1, pG13)
diff --git a/tests/test_lib_basics.py b/tests/test_lib_basics.py
index 5c92f04..dc42892 100644
--- a/tests/test_lib_basics.py
+++ b/tests/test_lib_basics.py
@@ -207,7 +207,7 @@ def test_graph_props():
     Simple tests of per-graph properties
 
     """
-    
+
     g1 = tg.TinyGraph(10)
     g1.props['foo'] = 'bar'
 
@@ -217,9 +217,9 @@ def test_graph_props():
     assert tg.util.graph_equality(g1, g2)
 
     g2.props['baz'] = 7
-    
+
     assert not tg.util.graph_equality(g1, g2)
-    
+
 
 @pytest.mark.parametrize("test_name", [k for k in suite.keys()])
 def test_copy_suite(test_name):
@@ -228,5 +228,112 @@ def test_copy_suite(test_name):
     """
     for g in suite[test_name]:
         g1 = g.copy()
-        assert tg.util.graph_equality(g1, g)
-        
+        assert tg.util.graph_equality(g, g1)
+
+        # Change g1 but not g
+        g1.add_vert_prop('useless_vertex_property', np.bool)
+        assert not tg.util.graph_equality(g, g1)
+
+
+def test_sequence_adjacency():
+    """
+    Ensure that sequences can be used to modify the adjacency matrix compactly
+    """
+    g = tg.TinyGraph(3, np.int)
+    # Edges:
+    g[[0, 1, 2], [1, 2, 0]] = np.array([1, 2, 3])
+
+    # Desired effect on adjacency matrix
+    assert np.array_equal(g.adjacency, np.array([[0, 1, 3], [1, 0, 2], [3, 2, 0]]))
+
+    # And __getitem__ fetches just a 3-item array rather than something weird
+    assert np.array_equal(g[[0, 1, 2], [1, 2, 0]], [1, 2, 3])
+
+    # Conflicting writes are dealt with
+    g[[0, 1], [1, 0]] = [7, 8]
+    # still symmetric!
+    assert np.array_equal(g.adjacency, g.adjacency.T)
+
+    # Add an edge from 0 to 2
+    g[range(1), range(2, 3)] = 13
+    assert g.adjacency[0, 2] == 13
+
+    # Zero-out everything
+    g[[0, 1, 2], [1, 2, 0]] = 0
+    assert np.all(g.adjacency == 0)
+
+    # Ensure tuples work
+    g[(0,), (1,)] = 1
+    assert g.adjacency[1, 0] == 1
+    g[(0, 1), (1, 2)] = 2
+    assert g.adjacency[1, 0] == 2
+    assert g.adjacency[2, 1] == 2
+    g[(0, 1), (1, 2)] = (3, 5)
+    assert g.adjacency[1, 0] == 3
+    assert g.adjacency[2, 1] == 5
+
+def test_sequence_adjacency_errors():
+    """
+    Test the error-handling for poorly setting adjacency matrix values
+    """
+    g = tg.TinyGraph(3, np.int)
+    with pytest.raises(KeyError):
+        g[[0, 0, 0], [1, 2]] = 1
+
+    with pytest.raises(IndexError):
+        # Attempt to set self-edges
+        g[[0, 1], [0, 1]] = 5
+
+    with pytest.raises(ValueError):
+        # length mismatch -> numpy shape mismatch
+        g[[0, 1], [1, 2]] = [5, 2, 6]
+
+def test_sequence_vprop():
+    """
+    Test that sequences can be used for assigning vertex properties
+    """
+    g = tg.TinyGraph(3, vp_types={'name':np.dtype('<U10'), 'number':np.int})
+    g.v['name'][[0, 2, 1]] = ['a', 'c', 'b']
+    g.v['number'][[1, 2, 0]] = [2, 3, 1]
+
+    assert np.array_equal(g.v['name'], ['a', 'b', 'c'])
+    assert np.array_equal(g.v['number'], [1, 2, 3])
+
+
+def test_sequence_eprop():
+    """
+    Test that sequences can be used for assigning edge properties
+    """
+    g = tg.TinyGraph(3, ep_types={'edgecolor':np.int})
+
+    # Edges: 0-2, 1-2
+    g[[0, 1], [2, 2]] = [1, 1]
+    g.e['edgecolor'][[0, 1], [2, 2]] = [1, 2]
+    assert np.array_equal(g.e_p['edgecolor'], np.array([[0, 0, 1], [0, 0, 2], [1, 2, 0]]))
+
+    # Ensure some kind of consistency (symmetric e_p)
+    g[0, 1] = 5
+    g.e['edgecolor'][[0, 1], [1, 0]] = [7, 8]
+    assert np.array_equal(g.e_p['edgecolor'], g.e_p['edgecolor'].T)
+
+    # Edge deletion results in property deletion
+    g[[0, 1], [1, 2]] = (0, 1)
+    assert g.e_p['edgecolor'][1, 0] == 0
+    assert g.e_p['edgecolor'][1, 2] == 2
+
+def test_sequence_eprop_errors():
+    """
+    Test the error-handling for poorly setting edge properties with sequences
+    """
+    g = tg.TinyGraph(3, ep_types={'edgecolor':np.int})
+
+    with pytest.raises(KeyError):
+        g.e['edgecolor'][[0, 0, 0], [1, 2]] = 1
+
+    with pytest.raises(IndexError):
+        # Attempt to set self-edges
+        g.e['edgecolor'][[0, 1], [0, 1]] = 5
+
+    with pytest.raises(IndexError):
+        # length mismatch
+        g.e['edgecolor'][[0, 1], [1, 2]] = [5, 2, 6]
diff --git a/tinygraph/tinygraph.py b/tinygraph/tinygraph.py
index 0f1a6f6..d2319c5 100644
--- a/tinygraph/tinygraph.py
+++ b/tinygraph/tinygraph.py
@@ -44,7 +44,7 @@ def __init__(self, g, prop):
             g (TinyGraph): The graph which EdgeProxy is accessing a property of.
                 EdgeProxy will alter one property in g.e_p.
             property (string): The name of the property to access.
-        
+
         Outputs:
             ep (EdgeProxy): new EdgeProxy object.
         """
@@ -62,6 +62,8 @@ def __setitem__(self, key, value):
 
         Inputs:
             key ((int, int)): Endpoints of edge to set the property of.
+               Also accepts sequences (iterable) in place of ints, numpy-style
+               (usage: ([s1, s2, ...], [t1, t2, ...]) to modify edges (s1, t1), (s2, t2), ...)
             value (dtype): Value to set edge property to.
 
         Outputs:
@@ -71,13 +73,29 @@ def __setitem__(self, key, value):
             raise KeyError("Expecting exactly two endpoints.")
         elif len(key) != 2:
             raise KeyError("Expecting exactly two endpoints.")
-        else:
-            e1, e2 = key
-            if self.__g[e1, e2] == default_zero(self.dtype):
-                raise IndexError("No such edge.")
-            else:
-                self.__g.e_p[self.__prop][e1, e2] = value
-                self.__g.e_p[self.__prop][e2, e1] = value
+
+        e1, e2 = key
+        len1 = getattr(e1, '__len__', lambda: 1)()
+        len2 = getattr(e2, '__len__', lambda: 1)()
+
+        if len1 != len2:
+            raise KeyError("Mismatched sequence lengths!")
+        if len1 == 0:
+            raise KeyError("Zero-length key passed!")
+
+        if np.any(self.__g[e1, e2] == default_zero(self.dtype)):
+            raise IndexError("Missing at least one edge.")
+
+        # Enforce consistent writes (in case of (0, 1) and (1, 0))
+        if len1 > 1:
+            reorder = lambda x, y: (x, y) if x<y else (y, x)
+            e1 = list(e1)
+            e2 = list(e2)
+            for i in range(len1):
+                e1[i], e2[i] = reorder(e1[i], e2[i])
+
+        self.__g.e_p[self.__prop][e1, e2] = value
+        self.__g.e_p[self.__prop][e2, e1] = value
 
     def __getitem__(self, key):
         """
@@ -93,12 +111,20 @@ def __getitem__(self, key):
             raise KeyError("Expecting exactly two endpoints.")
         elif len(key) != 2:
             raise KeyError("Expecting exactly two endpoints.")
-        else:
-            e1, e2 = key
-            if self.__g[e1, e2] == default_zero(self.dtype):
-                raise IndexError("No such edge.")
-            else:
-                return self.__g.e_p[self.__prop][e1, e2]        
+
+        e1, e2 = key
+        len1 = getattr(e1, '__len__', lambda: 1)()
+        len2 = getattr(e2, '__len__', lambda: 1)()
+
+        if len1 != len2:
+            raise KeyError("Mismatched sequence lengths!")
+        if len1 == 0:
+            raise KeyError("Zero-length key passed!")
+
+        if np.any(self.__g[e1, e2] == default_zero(self.dtype)):
+            raise IndexError("Missing at least one edge.")
+
+        return self.__g.e_p[self.__prop][e1, e2]
 
 class EdgeProxyGenerator:
     """
@@ -139,7 +165,7 @@ def __getitem__(self, key):
             key (string): The property name to access
 
         Outputs:
-            ep (EdgeProxy): An EdgeProxy object with access to the desired 
+            ep (EdgeProxy): An EdgeProxy object with access to the desired
                 property and the current graph.
         """
         return EdgeProxy(self.__g, key)
@@ -178,7 +204,7 @@ def __init__(self, node_N, adj_type=np.int32, vp_types={}, ep_types={}):
         self.v = {}
         self.e_p = {}
         self.e = EdgeProxyGenerator(self)
-        
+
         for k, dt in vp_types.items():
             self.add_vert_prop(k, dt)
 
@@ -186,7 +212,7 @@ def __init__(self, node_N, adj_type=np.int32, vp_types={}, ep_types={}):
             self.add_edge_prop(k, dt)
 
         self.props = {}
-        
+
     @property
     def node_N(self):
         return self.__node_N
@@ -201,7 +227,7 @@ def edge_N(self):
 
     def add_vert_prop(self, name, dtype):
         """
-        Add the vertex property named 'name' to the graph. 
+        Add the vertex property named 'name' to the graph.
 
         Inputs:
              name : name (string)
@@ -209,22 +235,22 @@ def add_vert_prop(self, name, dtype):
         """
         if name in self.v:
             raise KeyError(f"Graph already has vertex property named {name}")
-        
+
         self.v[name] = np.zeros(self.__node_N, dtype=dtype)
 
     def add_edge_prop(self, name, dtype):
         """
-        Add the edge property named 'name' to the graph. 
-        
-        Inputs: 
+        Add the edge property named 'name' to the graph.
+
+        Inputs:
              name : name (string)
              dtype : numpy dtype
 
         """
-        
+
         if name in self.e_p:
             raise KeyError(f"Graph already has edge property named {name}")
-        
+
         self.e_p[name] = np.zeros((self.__node_N, self.__node_N), dtype=dtype)
 
     def remove_vert_prop(self, name):
@@ -237,7 +263,7 @@ def remove_vert_prop(self, name):
         """
 
         del self.v[name]
-        
+
     def remove_edge_prop(self, name):
         """
         Removes the indicated edge property from the graph
@@ -248,7 +274,7 @@ def remove_edge_prop(self, name):
         """
 
         del self.e_p[name]
-        
+
 
 
     def add_node(self, props = {}, **kwargs):
@@ -267,12 +293,7 @@ def add_node(self, props = {}, **kwargs):
             None - modifications are made in place.
 
         """
-        # # New Adjacency matrix
-        # # Currently discards the old adjacency matrix entirely
-        # new_adj = np.zeros((self.node_N+1, self.node_N+1), dtype=self.adj_type)
-        # new_adj[:self.node_N, :self.node_N] = self.adjacency
-        # self.adjacency = new_adj
-
+        # New Adjacency matrix
         self.adjacency = np.insert(self.adjacency, self.__node_N, 0, axis=0)
         self.adjacency = np.insert(self.adjacency, self.__node_N, 0, axis=1)
 
@@ -322,15 +343,18 @@ def remove_node(self, n):
         # Update the node count
         self.__node_N -= 1
 
-    def __setitem__(self, key, newValue):
+    def __setitem__(self, key, new_value):
         """
         Create an edge or change the weight of an existing edge. This operation
-        is fast. Edges are undirected. If an existing edge is set to its zero 
+        is fast. Edges are undirected. If an existing edge is set to its zero
         value, it is removed, setting all of its property values to their zeros.
 
         Inputs:
             key (int, int): Endpoint nodes of edge.
-            newValue (adj_type): Weight of edge.
+               Also accepts sequences (iterable) in place of ints, numpy-style
+               (usage: ([s1, s2, ...], [t1, t2, ...]) to modify edges (s1, t1), (s2, t2), ...)
+            value (dtype): Value to set edge property to.
+            new_value (adj_type): Weight of edge.
 
         Outputs:
             None - modifications are made in place.
@@ -340,14 +364,44 @@ def __setitem__(self, key, newValue):
         elif len(key) != 2:
             raise KeyError("Expecting exactly two endpoints.")
         e1, e2 = key
-        if e1 == e2:
+        lenv = getattr(new_value, '__len__', lambda: 1)()
+        len1 = getattr(e1, '__len__', lambda: 1)()
+        len2 = getattr(e2, '__len__', lambda: 1)()
+
+        if len1 == 0:
+            raise KeyError("Zero-length key passed!")
+        if len1 != len2:
+            raise KeyError("Mismatched sequence lengths!")
+        if np.any(e1 == e2):
             raise IndexError("Self-loops are not allowed.")
-        self.adjacency[e1, e2] = newValue
-        self.adjacency[e2, e1] = newValue
-        if newValue == default_zero(self.adjacency.dtype):
+
+        # Force e1's indices to be strictly less (if a sequence)
+        # that way, conflicting writes (e.g. entry (0, 1) and (1, 0))
+        # will be dealt with by numpy and leave a symmetric
+        # adjacency matrix
+        if len1 > 1:
+            reorder = lambda x, y: (x, y) if x<y else (y, x)
+            e1 = np.array(list(e1))
+            e2 = np.array(list(e2))
+            for i in range(len1):
+                e1[i], e2[i] = reorder(e1[i], e2[i])
+
+        self.adjacency[e1, e2] = new_value
+        self.adjacency[e2, e1] = new_value
+
+        # Zero-out properties when edges are deleted
+        if lenv == 1:
+            if new_value == default_zero(self.adjacency.dtype):
+                for k, prop in self.e_p.items():
+                    self.e_p[k][e1, e2] = default_zero(prop.dtype)
+                    self.e_p[k][e2, e1] = default_zero(prop.dtype)
+        else:
+            del_edges = np.array(list(new_value)) == default_zero(self.adjacency.dtype)
+            d1 = e1[del_edges]
+            d2 = e2[del_edges]
             for k, prop in self.e_p.items():
-                self.e_p[k][e1, e2] = default_zero(prop.dtype)
-                self.e_p[k][e2, e1] = default_zero(prop.dtype)
+                self.e_p[k][d1, d2] = default_zero(prop.dtype)
+                self.e_p[k][d2, d1] = default_zero(prop.dtype)
 
     def __getitem__(self, key):
         """
@@ -363,7 +417,7 @@ def __getitem__(self, key):
             raise KeyError("Expecting exactly two endpoints.")
         elif len(key) != 2:
             raise KeyError("Expecting exactly two endpoints.")
-        return self.adjacency[key[0]][key[1]]
+        return self.adjacency[key[0], key[1]]
 
     def copy(self):
         """
@@ -391,7 +445,7 @@ def copy(self):
 
         for k, v in self.props.items():
             new_graph.props[k] = deepcopy(v)
-            
+
         return new_graph
 
     def get_vert_props(self, n, vert_props = None):
@@ -449,10 +503,10 @@ def __repr__(self):
         for i, props in self.vertices(vert_props = self.v.keys()):
             rep += str(i) + ": " + str(props) + "\n"
         rep += "\nEdges:\n"
-        for i,j,w,props in self.edges(weight = True,edge_props = self.e.keys()): 
+        for i,j,w,props in self.edges(weight = True,edge_props = self.e.keys()):
             rep += "(" + str(i) + ", " + str(j) + "): Weight - " + str(w) +\
                 ", Props - " + str(props) + "\n"
-        return rep[:-1] # strip last newline 
+        return rep[:-1] # strip last newline
 
     def get_neighbors(self, n):
         """
@@ -473,7 +527,7 @@ def get_neighbors(self, n):
 
     def edges(self, weight = False, edge_props = None):
         """
-        Get a list of the edges by endpoint nodes, optionally with their weight 
+        Get a list of the edges by endpoint nodes, optionally with their weight
         and some properties.
 
         Inputs:
@@ -487,12 +541,12 @@ def edges(self, weight = False, edge_props = None):
             edges ([edge]): A list of edges, where each edge is represented by a
                 tuple. The first two elements of the tuple are the endpoints of
                 the edge. If weights is true, the third element is the weight of
-                the edge. If edge_props is not empty, a dictionary mapping the 
-                properties provided to the value for the edge is the final 
+                the edge. If edge_props is not empty, a dictionary mapping the
+                properties provided to the value for the edge is the final
                 element of the tuple.
         """
         edges = []
-        for i, j in np.argwhere(self.adjacency != 
+        for i, j in np.argwhere(self.adjacency !=
                                     default_zero(self.adjacency.dtype)):
             if i < j:
                 e = (i, j)
@@ -515,10 +569,10 @@ def vertices(self, vert_props = []):
 
         Outputs:
             nodes ([node]): A list of nodes, where each node is represented by a
-                tuple. The first element of the tuple is the node index. The 
+                tuple. The first element of the tuple is the node index. The
                 second element is a map from the provided node properties to
                 the values at the node. Even when no properties are provided, a
-                map is returned, since the list of vertices is simply 0...N-1, 
+                map is returned, since the list of vertices is simply 0...N-1,
                 which can be retrieved more efficiently in other ways.
         """
         nodes = []