sped up simplegraph.py with 10-30%

simplegraph.py

@@ -37,7 +37,7 @@ def find_all_paths(graph, start, end, path=[]):
                 paths.append(newpath)
     return paths
 
-
+"""
 def find_shortest_path(graph, start, end, path=[], level=0):
     #print("start:", start, "end:",end)
     path = path + [start]
@@ -69,17 +69,69 @@ def find_shortest_path(graph, start, end, path=[], level=0):
                 shortest = b
         path = [start] + shortest
         return path
+"""
+def find_shortest_path(graph, start, end, path=[]):
+    """this is called first, fsp_post is called second"""
+    #print("start:", start, "end:",end)
+    path = path + [start]
+#    print("PATH :",path, "start",start,"end",end)
+    if start == end and end not in graph[start]:
+        # from the next node, which is the fastest way to the end?
+        alt0, alt1 = graph[start]  # get the two alternatives
+        first = find_shortest_path(graph, alt0, end, [])
+        second = find_shortest_path(graph, alt1, end, [])
+        shortest = fsp_select_shortest(first, second)
+        path = [start] + shortest
+        return path
+    elif start == end:
+        return path
+    if not start in graph.keys():
+       #     print("error, start node not in graph")
+        return None
+    shortest = None
+    for node in graph[start]:
+        if node not in path:
+            newpath = fsp_post(graph, node, end, path)
+            if newpath:
+                if not shortest or len(newpath) < len(shortest):
+                    shortest = newpath
+    return shortest
+
+def fsp_select_shortest(first, second):
+    mini = min(len(first), len(second))
+    if len(first) == len(second):
+        # lengths are equal.
+        if 'IDLE' in first:
+            shortest = first
+        if 'IDLE' in second:
+            shortest = second
+        else:
+            shortest = first
+
+    else:
+        if mini == len(first):
+            shortest = first
+        else:
+            shortest = second
+    return shortest
 
-#    elif start == end:
-#        path = find_path_back(graph, start, path)
+def fsp_post(graph, start, end, path=[]):
+    """faster version of find_shortest_path, because of checks in first call"""
+    #print("start:", start, "end:",end)
+    path = path + [start]
+#    print("PATH :",path, "start",start,"end",end)
+    if start == end:
+        return path
     if not start in graph.keys():
        #     print("error, start node not in graph")
         return None
     shortest = None
     for node in graph[start]:
         if node not in path:
-            newpath = find_shortest_path(graph, node, end, path, level=level+1)
+            newpath = fsp_post(graph, node, end, path)
             if newpath:
                 if not shortest or len(newpath) < len(shortest):
                     shortest = newpath
     return shortest
+    
+