core.Keep pipeline module for removing all but the specified keys from frames

Author: arahlin

core/python/util.py

@@ -12,6 +12,18 @@ def Delete(frame, keys=[], type=None):
         if key in frame:
             del frame[key]
 
+@indexmod
+def Keep(frame, keys=[], type=None):
+    '''
+    Deletes all but specified keys from frame.  If optional type specified, only acts on frames of the given type.
+    '''
+    if type is not None and frame.type != type:
+        return
+
+    for key in list(frame.keys()):
+        if key not in keys:
+            del frame[key]
+
 @indexmod
 def Rename(frame, keys={}, type=None):
     '''