Add support for a custom null marker. (#3776)

Author: lukesneeringer

bigquery/google/cloud/bigquery/table.py

@@ -1043,7 +1043,8 @@ def upload_from_file(self,
  skip_leading_rows=None,
  write_disposition=None,
  client=None,
- job_name=None):
+ job_name=None,
+ null_marker=None):
  """Upload the contents of this table from a file-like object.
 
  :type file_obj: file
@@ -1116,6 +1117,9 @@ def upload_from_file(self,
  :param job_name: Optional. The id of the job. Generated if not
  explicitly passed in.
 
+ :type null_marker: str
+ :param null_marker: Optional. A custom null marker (example: "\\N")
+
  :rtype: :class:`~google.cloud.bigquery.jobs.LoadTableFromStorageJob`
 
  :returns: the job instance used to load the data (e.g., for
@@ -1135,7 +1139,7 @@ def upload_from_file(self,
  encoding, field_delimiter,
  ignore_unknown_values, max_bad_records,
  quote_character, skip_leading_rows,
- write_disposition, job_name)
+ write_disposition, job_name, null_marker)
 
  try:
  created_json = self._do_upload(
@@ -1157,7 +1161,8 @@ def _configure_job_metadata(metadata, # pylint: disable=too-many-arguments
  quote_character,
  skip_leading_rows,
  write_disposition,
- job_name):
+ job_name,
+ null_marker):
  """Helper for :meth:`Table.upload_from_file`."""
  load_config = metadata['configuration']['load']
 
@@ -1194,6 +1199,9 @@ def _configure_job_metadata(metadata, # pylint: disable=too-many-arguments
  if job_name is not None:
  load_config['jobReference'] = {'jobId': job_name}
 
+ if null_marker is not None:
+ load_config['nullMarker'] = null_marker
+
 
 def _parse_schema_resource(info):
  """Parse a resource fragment into a schema field.

bigquery/tests/unit/test_table.py

@@ -1868,7 +1868,8 @@ def test_upload_file_resumable_metadata(self):
  'quote_character': '"',
  'skip_leading_rows': 1,
  'write_disposition': 'WRITE_APPEND',
- 'job_name': 'oddjob'
+ 'job_name': 'oddjob',
+ 'null_marker': r'\N',
  }
 
  expected_config = {
@@ -1878,7 +1879,7 @@ def test_upload_file_resumable_metadata(self):
  'destinationTable': {
  'projectId': table._dataset._client.project,
  'datasetId': table.dataset_name,
- 'tableId': table.name
+ 'tableId': table.name,
  },
  'allowJaggedRows': config_args['allow_jagged_rows'],
  'allowQuotedNewlines':
@@ -1892,9 +1893,10 @@ def test_upload_file_resumable_metadata(self):
  'quote': config_args['quote_character'],
  'skipLeadingRows': config_args['skip_leading_rows'],
  'writeDisposition': config_args['write_disposition'],
- 'jobReference': {'jobId': config_args['job_name']}
- }
- }
+ 'jobReference': {'jobId': config_args['job_name']},
+ 'nullMarker': config_args['null_marker'],
+ },
+ },
  }
 
  do_upload_patch = self._make_do_upload_patch(