184 

   185 def groupby(target, group_key):

   186   """Groups a list of dictionaries by group_key.

   187   """

   188 

   189   result = {}

   190 

   191   for value in target:

   192     key_value = value[group_key]

   193 

   194     if not key_value in result:

   195       result[key_value] = []

   196 

   197     result[key_value].append(value)

   198 

   199   return result