parameters: (self,prefixList,targetExtension=None)
docstring: if no target extension, then list directories at the tip of the prefix list
docstring_summary: if no target extension, then list directories at the tip of the prefix list
docstring_tokens: if no target extension then list directories at the tip of the prefix list
function: def __init__(self,prefixList,targetExtension=None) :
          """
          if no target extension, then list directories at the tip of the prefix list
          """
          self.prefixList=prefixList
          self.targetExtension=targetExtension
function_tokens: def __init__ ( self , prefixList , targetExtension = None ) : self . prefixList = prefixList self . targetExtension = targetExtension