text: # -*- coding: utf-8 -*-
  #
  # Copyright 2018 Google LLC
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     https://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  """System tests for reading rows from tables."""
  
  import os
  
  import numpy
  import pytest
  
  from google.cloud import bigquery_storage_v1beta1
  
  
  @pytest.fixture()
  def project_id():
      return os.environ["PROJECT_ID"]
  
  
  @pytest.fixture()
  def client():
      return bigquery_storage_v1beta1.BigQueryStorageClient()
  
  
  @pytest.fixture()
  def table_reference():
      table_ref = bigquery_storage_v1beta1.types.TableReference()
      table_ref.project_id = "bigquery-public-data"
      table_ref.dataset_id = "usa_names"
      table_ref.table_id = "usa_1910_2013"
      return table_ref
  
  
  @pytest.fixture()
  def small_table_reference():
      table_ref = bigquery_storage_v1beta1.types.TableReference()
      table_ref.project_id = "bigquery-public-data"
      table_ref.dataset_id = "utility_us"
      table_ref.table_id = "country_code_iso"
      return table_ref
  
  
  def test_read_rows_full_table(client, project_id, small_table_reference):
      session = client.create_read_session(
          small_table_reference, "projects/{}".format(project_id), requested_streams=1
      )
  
      stream_pos = bigquery_storage_v1beta1.types.StreamPosition(
          stream=session.streams[0]
      )
      blocks = list(client.read_rows(stream_pos))
  
      assert len(blocks) > 0
      block = blocks[0]
      assert block.status.estimated_row_count > 0
      assert len(block.avro_rows.serialized_binary_rows) > 0
  
  
  def test_read_rows_to_dataframe(client, project_id):
      table_ref = bigquery_storage_v1beta1.types.TableReference()
      table_ref.project_id = "bigquery-public-data"
      table_ref.dataset_id = "new_york_citibike"
      table_ref.table_id = "citibike_stations"
      session = client.create_read_session(
          table_ref, "projects/{}".format(project_id), requested_streams=1
      )
      stream_pos = bigquery_storage_v1beta1.types.StreamPosition(
          stream=session.streams[0]
      )
  
      frame = client.read_rows(stream_pos).to_dataframe(
          session, dtypes={"latitude": numpy.float16}
      )
  
      # Station ID is a required field (no nulls), so the datatype should always
      # be integer.
      assert frame.station_id.dtype.name == "int64"
      assert frame.latitude.dtype.name == "float16"
      assert frame.longitude.dtype.name == "float64"
      assert frame["name"].str.startswith("Central Park").any()
  
  
  def test_split_read_stream(client, project_id, table_reference):
      session = client.create_read_session(
          table_reference, parent="projects/{}".format(project_id)
      )
  
      split = client.split_read_stream(session.streams[0])
  
      assert split.primary_stream is not None
      assert split.remainder_stream is not None
      assert split.primary_stream != split.remainder_stream
  