def export_date_time(format):

  def export_date_time_lambda(value):
    if not value:
      return ''
    return datetime.datetime.strftime(value, format)

  return export_date_time_lambda
A wrapper around strftime. Also returns '' if the input is None.
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/ext/bulkload/transform.py/export_date_time