LESS User Manual
The major user manual in English:
PyLessSDK API documentation
This link lists all the available functions and properties provided by PyLessSDK. However, when writing code, except of looking up the API list, another convenient way is to use the Python Code Generator provided by LESS GUI. When you create a simulation project using GUI, click 【Tools】【Generate Python Code】，then you will get a py file, which contains the code corresponding to the simulation created with GUI. With this code, you can modify the code according to your own needs.
Video tutorial （中文）