def get_converters(self, expressions):
    converters = {}
    for (i, expression) in enumerate(expressions):
        if expression:
            backend_converters = self.connection.ops.get_db_converters(expression)
            field_converters = expression.get_db_converters(self.connection)
            if (backend_converters or field_converters):
                converters[i] = ((backend_converters + field_converters), expression)
    return converters
def get_converters(self, expressions):
    converters = {}
    for (i, expression) in enumerate(expressions):
        if expression:
            backend_converters = self.connection.ops.get_db_converters(expression)
            field_converters = expression.get_db_converters(self.connection)
            if (backend_converters or field_converters):
                converters[i] = ((backend_converters + field_converters), expression)
    return converters