Abstract: An observation control system is the foundation to support automatic observations by any radio telescope. Traditional observation control systems are usually coded using a compiled language, which is of higher efficiency compared with interpreted languages. Indeed, observation control systems are usually programmed using the C or C++ languages. However, the high execution efficiency of C/C++ is at the cost of a long development cycle, which is not only time consuming but also requires considerable skills for the developers. The development of computer hardware performance, as well as the optimization of the just-in-time compiler for new interpreted languages such as Python, provides a good balance between execution and development efficiency. In this paper, we introduce the observation control system developed for the Kunming 40-meter radio telescope run by Yunnan Observatories, Chinese Academy of Sciences. The system is developed mainly with the Python language, and we have optimized computationally intensive components with C++. We demonstrate that it is possible to achieve the required functionality and control precision with such a Python-C++ programming paradigm. The performance of the control system is also assessed in this paper, demonstrating that satisfactory pointing accuracy and user experience can be attained.