Connect a Python project to a Processing sketch and communicate to Arduino. Python and Processing have infinite applications, one of them is to talk to Arduino. There are endless possibilties when you link Arduino to a python or a processing sketch. There are numerous times when you need your Arduino to talk to the computer and vice-versa. It makes your project more interactive.
You can either connect your Arduino directly to Python or use a bridge i.e., connect both of them to Processing, because some arduino boards cannot support more than one serial communication. So if one of them communicates with the board then it will be busy for the other. All Arduino boards have at least one serial port (also known as a UART or USART), and some have several.