_load_table_from_json.py

def _load_table_from_json(bucket_name, file_name, tableSchema, tableName):
  blob = CS.get_bucket(bucket_name).blob(file_name)
  #! source data file format must be outer array JSON:

  body = json.loads(blob.download_as_string())
  table_id = BQ.dataset(BQ_DATASET).table(tableName)

  job_config.source_format = bigquery.SourceFormat.NEWLINE_DELIMITED_JSON,
  job_config.write_disposition = 'WRITE_APPEND'

  schema = create_schema_from_yaml(tableSchema) 
  job_config.schema = schema

  load_job = BQ.load_table_from_json(
       body,
       table_id,
       job_config=job_config,
       )   

  load_job.result()  # Waits for table load to complete.
  print("Job finished.")