def _parse_date_columns(data_frame, parse_dates):
parse_dates = _process_parse_dates_argument(parse_dates)<EOL>for col_name, df_col in data_frame.iteritems():<EOL><INDENT>if is_datetime64tz_dtype(df_col) or col_name in parse_dates:<EOL><INDENT>try:<EOL><INDENT>fmt = parse_dates[col_name]<EOL><DEDENT>except TypeError:<EOL><INDENT>fmt = None<EOL><DEDENT>data_frame[col_name] = _handle_date_column(df_col, format=fmt)<EOL><DEDENT><DEDENT>return data_frame<EOL>
Force non-datetime columns to be read as such.
Supports both string formatted and integer timestamp columns.