some care in graph_coloring.pyx and hyperbolicity.pyx

Author: dcoudert

src/sage/graphs/graph_coloring.pyx

@@ -555,8 +555,7 @@ def vertex_coloring(g, k=None, value_only=False, hex_colors=False, solver=None,
                 return 0
             elif hex_colors:
                 return dict()
-            else:
-                return []
+            return []
         # - Independent set
         if not g.size():
             if value_only:
@@ -1754,11 +1753,10 @@ def round_robin(n):
             g.set_edge_label(n - 1, i, i)
             for j in range(1, (n - 1) // 2 + 1):
                 g.set_edge_label(my_mod(i - j, n - 1), my_mod(i + j, n - 1), i)
-        return g
     else:
         g = round_robin(n + 1)
         g.delete_vertex(n)
-        return g
+    return g
 
 
 def linear_arboricity(g, plus_one=None, hex_colors=False, value_only=False,

src/sage/graphs/hyperbolicity.pyx

@@ -327,8 +327,7 @@ cdef tuple hyperbolicity_basic_algorithm(int N,
     # Last, we return the computed value and the certificate
     if h_LB != -1:
         return (h_LB, certificate)
-    else:
-        return (-1, [])
+    return (-1, [])
 
 
 ######################################################################
@@ -825,10 +824,10 @@ cdef tuple hyperbolicity_BCCM(int N,
     # Last, we return the computed value and the certificate
     if not certificate:
         return (-1, [], h_UB)
-    else:
-        # When using far-apart pairs, the loops may end before improving the
-        # upper-bound
-        return (h, certificate, h_UB)
+
+    # When using far-apart pairs, the loops may end before improving the
+    # upper-bound
+    return (h, certificate, h_UB)
 
 
 ######################################################################
@@ -1043,10 +1042,10 @@ cdef tuple hyperbolicity_CCL(int N,
     # Last, we return the computed value and the certificate
     if not certificate:
         return (-1, [], h_UB)
-    else:
-        # When using far-apart pairs, the loops may end before improving the
-        # upper-bound
-        return (h, certificate, h_UB if GOTO_RETURN else h)
+
+    # When using far-apart pairs, the loops may end before improving the
+    # upper-bound
+    return (h, certificate, h_UB if GOTO_RETURN else h)
 
 
 def hyperbolicity(G,