def get_pandas_df(self, sql, parameters=None, dialect=None):
private_key = self._get_field('<STR_LIT>', None) or self._get_field('<STR_LIT>', None)<EOL>if dialect is None:<EOL><INDENT>dialect = '<STR_LIT>' if self.use_legacy_sql else '<STR_LIT>'<EOL><DEDENT>return read_gbq(sql,<EOL>project_id=self._get_field('<STR_LIT>'),<EOL>dialect=dialect,<EOL>verbose=False,<EOL>private_key=private_key)<EOL>
Returns a Pandas DataFrame for the results produced by a BigQuery
query. The DbApiHook method must be overridden because Pandas
doesn't support PEP 249 connections, except for SQLite. See:

https://github.com/pydata/pandas/blob/master/pandas/io/sql.py#L447
https://github.com/pydata/pandas/issues/6900

:param sql: The BigQuery SQL to execute.
:type sql: str
:param parameters: The parameters to render the SQL query with (not
    used, leave to override superclass method)
:type parameters: mapping or iterable
:param dialect: Dialect of BigQuery SQL – legacy SQL or standard SQL
    defaults to use `self.use_legacy_sql` if not specified
:type dialect: str in {'legacy', 'standard'}