def none_if_empty(fn):

  def wrapper(value):


    if value == '' or value is None or value == []:
      return None
    return fn(value)

  return wrapper
Determines the hooks to be run, in which order.
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/ext/bulkload/transform.py/none_if_empty--crossover with--dataset/ETHPy150Open pecan/pecan/pecan/core.py/PecanBase.determine_hooks