How to let others in and out and close the door behind them

Use a rubber band to fix one end to the door and the other end to the door frame (slightly inward). Try a few times and you will find the best position, that is, when you open the door to the maximum, the rubber will be in a straight line. When the door is opened, it can't be pulled back, so it is convenient to use it or move things when it is often open. When it is less than this angle (that is, when it is not opened to the maximum), the rubber band will be pulled open, and the greater the door is opened, the greater the pulling force will be, and the door will automatically close under the pulling force. The length of the rubber band depends on the tension. This method is very good, you might as well try it.