from google.appengine.ext import db

  def updateProjectsForGradingRecords(self, record_entities):

    """Updates StudentProjects using a list of GradingRecord entities.

    Args:

      record_entities: List of GradingRecord entities to process.

    """

    projects_to_update = []

    for record_entity in record_entities:

      project_entity = record_entity.project

      if project_entity.status in ['withdrawn', 'invalid']:

        # skip this project

        continue

      # get the key from the GradingRecord entity since that gets stored

      record_key = record_entity.key()

      passed_evals = project_entity.passed_evaluations

      failed_evals = project_entity.failed_evaluations

      # try to remove this GradingRecord from the existing list of evals

      if record_key in passed_evals:

        passed_evals.remove(record_key)

      if record_key in failed_evals:

        failed_evals.remove(record_key)

      # get the grade_decision from the GradingRecord

      grade_decision = record_entity.grade_decision

      # update GradingRecord lists with respect to the grading_decision

      if grade_decision == 'pass':

        passed_evals.append(record_key)

      elif grade_decision == 'fail':

        failed_evals.append(record_key)

      if project_entity.status != 'completed':

        # Only when the project has not been completed should the status be

        # updated to reflect the new setting of the evaluations.

        if len(failed_evals) == 0:

          # no failed evaluations present

          new_status = 'accepted'

        else:

          new_status = 'failed'

      else:

          new_status = project_entity.status

      # update the necessary fields and store it before updating

      project_entity.passed_evaluations = passed_evals

      project_entity.failed_evaluations = failed_evals

      project_entity.status = new_status

      projects_to_update.append(project_entity)

    # batch put the StudentProjects that need to be updated

    db.put(projects_to_update)