python/pycarbon/tests/hello_world/dataset_with_normal_schema/python_hello_world_carbon.py

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"""Minimal example of how to read samples from a dataset generated by `generate_external_dataset_carbon.py`
using plain Python"""

from __future__ import print_function

import argparse
import jnius_config

from pycarbon.reader import make_reader
from pycarbon.tests import DEFAULT_CARBONSDK_PATH


def python_hello_world(dataset_url='file:///tmp/carbon_external_dataset'):
  # Reading data from the non-Pycarbon Carbon via pure Python
  with make_reader(dataset_url, schema_fields=["id", "value1", "value2"]) as reader:
    for schema_view in reader:
      # make_reader() returns batches of rows instead of individual rows
      print("Batched read:\nid: {0} value1: {1} value2: {2}".format(
        schema_view.id, schema_view.value1, schema_view.value2))


if __name__ == '__main__':
  parser = argparse.ArgumentParser(description='Python hello world')
  parser.add_argument('-c', '--carbon-sdk-path', type=str, default=DEFAULT_CARBONSDK_PATH,
                      help='carbon sdk path')

  args = parser.parse_args()

  jnius_config.set_classpath(args.carbon_sdk_path)

  python_hello_world()