Update main for Python 3. Use .items() instead of .iteritems() (#7901)
Update main for Python 3. Use .items() instead of .iteritems() (#7901)


Co-authored-by: Mariatta Wijaya <7683b66f2e471b8a970191fffd8117639b4f3f38@users.noreply.github.com>

GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples