AttributeError when use_bqstorage_api=True on empty df

[Bizetremi]

The following error is thrown when using pandas_gbq.read_gbq with use_bqstorage_api=True when the query returns no data.

(use_bqstorage_api=True)
File '/env/local/lib/python3.7/site-packages/pandas_gbq/gbq.py', line 1034, in read_gbq
progress_bar_type=progress_bar_type,
File '/env/local/lib/python3.7/site-packages/pandas_gbq/gbq.py', line 532, in run_query
progress_bar_type=progress_bar_type,
File '/env/local/lib/python3.7/site-packages/pandas_gbq/gbq.py', line 576, in _download_results
df = _localize_df(schema_fields, df)
File '/env/local/lib/python3.7/site-packages/pandas_gbq/gbq.py', line 808, in _localize_df
if field['type'].upper() == 'TIMESTAMP' and df[column].dt.tz is None:
File '/env/local/lib/python3.7/site-packages/pandas/core/generic.py', line 5175, in getattr
return object.getattribute(self, name)
File '/env/local/lib/python3.7/site-packages/pandas/core/accessor.py', line 175, in get
accessor_obj = self._accessor(obj)
File '/env/local/lib/python3.7/site-packages/pandas/core/indexes/accessors.py', line 343, in new
raise AttributeError('Can only use .dt accessor with datetimelike ' 'values')
AttributeError: Can only use .dt accessor with datetimelike values

[tswast]

I'm not able to reproduce with a plain empty result set. This test passes:

def test_empty_results(method_under_test):
    """Test with an empty dataframe.

    See: https://github.com/pydata/pandas-gbq/issues/299
    """
    df = method_under_test(
        "SELECT * FROM (SELECT 1) AS tbl WHERE TRUE = FALSE;",
        use_bqstorage_api=True,
    )
    assert len(df.index) == 0

Based on the stacktrace, I'll try a query where a timestamp column is in the results.

[tswast]

Based on the stacktrace, I'll try a query where a timestamp column is in the results.

Confirmed. The test fails with the query "SELECT * FROM (SELECT TIMESTAMP('2020-02-11 16:33:32-06:00')) WHERE TRUE = FALSE;".