git grep -l 'import Digraph' | xargs sed -i.bak 's/import Digraph/import DiGraph/'

Author: Matthias Koeppe

src/sage/graphs/base/static_sparse_graph.pyx

@@ -231,7 +231,7 @@ cdef int init_short_digraph(short_digraph g, G, edge_labelled=False, vertex_list
     cdef int isdigraph
 
     from sage.graphs.graph import Graph
-    from sage.graphs.digraph import Digraph
+    from sage.graphs.digraph import DiGraph
 
     if isinstance(G, DiGraph):
         isdigraph = 1

src/sage/graphs/generic_graph.py

@@ -22348,7 +22348,7 @@ def automorphism_group(self, partition=None, verbosity=0,
         from sage.groups.perm_gps.partn_ref.refinement_graphs import search_tree
         from sage.groups.perm_gps.permgroup import PermutationGroup
         from sage.graphs.graph import Graph
-        from sage.graphs.digraph import Digraph
+        from sage.graphs.digraph import DiGraph
         from itertools import chain
         dig = (self._directed or self.has_loops())
 
@@ -22850,7 +22850,7 @@ def is_isomorphic(self, other, certificate=False, verbosity=0, edge_labels=False
             partition2 = other_vertices
         G_to = {u: i for i,u in enumerate(self_vertices)}
         from sage.graphs.graph import Graph
-        from sage.graphs.digraph import Digraph
+        from sage.graphs.digraph import DiGraph
         DoDG = DiGraph if self._directed else Graph
         H = DoDG(len(self_vertices), loops=G.allows_loops())
         HB = H._backend
@@ -23101,7 +23101,7 @@ class by some canonization function `c`. If `G` and `H` are graphs,
         # algorithm == 'sage':
         from sage.groups.perm_gps.partn_ref.refinement_graphs import search_tree
         from sage.graphs.graph import Graph
-        from sage.graphs.digraph import Digraph
+        from sage.graphs.digraph import DiGraph
         from itertools import chain
 
         dig = (self.has_loops() or self._directed)
@@ -24100,7 +24100,7 @@ def graph_isom_equivalent_non_edge_labeled_graph(g, partition=None, standard_lab
         False
     """
     from sage.graphs.graph import Graph
-    from sage.graphs.digraph import Digraph
+    from sage.graphs.digraph import DiGraph
     from itertools import chain
 
     g_has_multiple_edges = g.has_multiple_edges()

src/sage/groups/perm_gps/partn_ref/refinement_graphs.pyx

@@ -71,7 +71,7 @@ def isomorphic(G1, G2, partn, ordering2, dig, use_indicator_function, sparse=Fal
     cdef bint loops = 0
 
     from sage.graphs.graph import Graph
-    from sage.graphs.digraph import Digraph
+    from sage.graphs.digraph import DiGraph
     from sage.graphs.generic_graph import GenericGraph
     from copy import copy
     which_G = 1
@@ -381,7 +381,7 @@ def search_tree(G_in, partition, lab=True, dig=False, dict_rep=False, certificat
     cdef aut_gp_and_can_lab *output
     cdef PartitionStack *part
     from sage.graphs.graph import Graph
-    from sage.graphs.digraph import Digraph
+    from sage.graphs.digraph import DiGraph
     from sage.graphs.generic_graph import GenericGraph
     from copy import copy
     if isinstance(G_in, GenericGraph):

src/sage/matroids/linear_matroid.pyx

@@ -6033,7 +6033,7 @@ cdef class RegularMatroid(LinearMatroid):
         """
         # NEW VERSION, Uses Sage'S Graph Isomorphism
         from sage.graphs.graph import Graph
-        from sage.graphs.digraph import Digraph
+        from sage.graphs.digraph import DiGraph
         if self._r_hypergraph is not None:
             return (self._hypergraph_vertex_partition, self._hypergraph_tuples, self._r_hypergraph)
         cdef Matrix P = self._projection()