misc cleanup and minor optimizations

overviewer_core/util.py

@@ -26,6 +26,7 @@ import logging
 from cStringIO import StringIO
 import ctypes
 import platform
+from itertools import cycle, islice
 
 def get_program_path():
     if hasattr(sys, "frozen") or imp.is_frozen("__main__"):
@@ -79,6 +80,20 @@ def findGitVersion():
         except Exception:
             return "unknown"
 
+# http://docs.python.org/library/itertools.html
+def roundrobin(iterables):
+    "roundrobin('ABC', 'D', 'EF') --> A D E B F C"
+    # Recipe credited to George Sakkis
+    pending = len(iterables)
+    nexts = cycle(iter(it).next for it in iterables)
+    while pending:
+        try:
+            for next in nexts:
+                yield next()
+        except StopIteration:
+            pending -= 1
+            nexts = cycle(islice(nexts, pending))
+
 
 # Logging related classes are below