def validate_file_type(result, accept_file_types=UPLOAD_ACCEPT_FILE_TYPES):
    # only allow images to be posted to this handler
    if not accept_file_types.match(result.type):
        result.field.error_msg = 'accept_file_types'
        return False
    return True
Create a PilotDataService
dataset/ETHPy150Open gregorynicholas/flask-gae_blobstore/flask_gae_blobstore.py/validate_file_type--crossover with--dataset/ETHPy150Open saga-project/BigJob/pilot/api/data/api.py/PilotDataService.__init__