我正在尝试将Apache光束输出写入Bigquery Table，但它的下载失败，如下所示 . 请帮助 .

代码：

import logging
import apache_beam as beam
from mongodbio import ReadFromMongo

TABLE_SCHEMA = ('clause_type:STRING, count:INTEGER')

def transform_doc(document):
    data={str(document['clause_type']):int(document['count'])}
    return data


def run():
    connection_string = 'mongodb://localhost:27017'
    with beam.Pipeline(runner='DirectRunner') as pipeline:
        (pipeline
        | 'read' >> ReadFromMongo(connection_string, 'new', 'Data', 
          query={}, fields=['count','clause_type'])
        | 'transform' >> 
          beam.Map(transform_doc).with_output_types(str)
        | 'save' >> beam.io.WriteToBigQuery('<table_name>',schema=TABLE_SCHEMA,create_disposition=beam.io.BigQueryDisposition.CREATE_IF_NEEDED,write_disposition=beam.io.BigQueryDisposition.WRITE_APPEND))

 if __name__ == '__main__':
    logging.getLogger().setLevel(logging.DEBUG)
    run()

错误：

index: <index number>>, <InsertErrorsValueListEntry
  errors: [<ErrorProto
  debugInfo: u'generic::not_found: no such field.'
  location: u'fiscal year'
  message: u'no such field.'
  reason: u'invalid'>]
python google-bigquery apache-beam