## execute(input_file_name, output_file_name, field_names, field_values) {#str_str_strlist_objectlist} Performs a mail merge operation for a single record. ```python def execute(self, input_file_na...... input_stream: io.BytesIO, output_stream: io.BytesIO, save_format:...--- | --- | | input_stream | io.BytesIO | The input file stream...