I need to make the Raspberry Pi communicate with the Arduino via USB Cable. From this, I will use the port on the USB which supports Serial Communication. However I also need to make the Raspberry Pi communicate through Bluetooth in a Mobile App via Serial Communication as well. Since both Serial devices use different ports according the the Raspberry Pi 3 Model B documentation, can it communicate at the same time? (The Arduino to Raspberry Pi and Raspberry Pi to Mobile App). The Bluetooth uses the /dev/ttyAMA0 port then I will use an USB port to connect the Pi to the Arduino.
Example using pySerial library.
serialArduino = serial.Serial('/dev/ttyACM0', 9600)
serialBluetooth = serial.Serial('/dev/ttyAMA0', 9600)