ENH: query standard price (USD) presentation (googleapis#71)

docs/source/changelog.rst

@@ -8,7 +8,7 @@ Changelog
 - The dataframe passed to ```.to_gbq(...., if_exists='append')``` needs to contain only a subset of the fields in the BigQuery schema. (:issue:`24`)
 - Use the `google-auth <https://google-auth.readthedocs.io/en/latest/>`__ library for authentication because oauth2client is deprecated. (:issue:`39`)
 - ``read_gbq`` now has a ``auth_local_webserver`` boolean argument for controlling whether to use web server or console flow when getting user credentials. Replaces `--noauth_local_webserver` command line argument. (:issue:`35`)
-- ``read_gbq`` now displays the BigQuery Job ID in verbose output. (:issue:`70`)
+- ``read_gbq`` now displays the BigQuery Job ID and standard price in verbose output. (:issue:`70` and :issue:`71`)
 
 0.1.6 / 2017-05-03
 ------------------

pandas_gbq/gbq.py

@@ -202,6 +202,10 @@ def __init__(self, project_id, reauth=False, verbose=False,
         self.credentials = self.get_credentials()
         self.service = self.get_service()
 
+        # BQ Queries costs $5 per TB. First 1 TB per month is free
+        # see here for more: https://cloud.google.com/bigquery/pricing
+        self.query_price_for_TB = 5. / 2**40  # USD/TB
+
     def get_credentials(self):
         if self.private_key:
             return self.get_service_account_credentials()
@@ -545,8 +549,10 @@ def run_query(self, query, **kwargs):
             else:
                 bytes_processed = int(query_reply.get(
                     'totalBytesProcessed', '0'))
-                self._print('Query done.\nProcessed: {}\n'.format(
+                self._print('Query done.\nProcessed: {}'.format(
                     self.sizeof_fmt(bytes_processed)))
+                self._print('Standard price: ${:,.2f} USD\n'.format(
+                    bytes_processed * self.query_price_for_TB))
 
             self._print('Retrieving results...')