google-cloud-spanner

I am trying to read a table from a Google spanner database, and write it to a text file to do a backup, using google dataflow with the python sdk. I have written the following script: from __future__ import absolute_import import argparse import itertools import logging import re import time import datetime as dt import logging import apache_beam as beam from apache_beam.io import iobase from apache_beam.io import WriteToText from apache_beam.io.range_trackers import OffsetRangeTracker, UnsplittableRangeTracker from apache_beam.metrics import Metrics from apache_beam.options.pipeline_options