```python
import serial

from serial.tools import list_ports
ports = list(list_ports.comports())
i = 1
for p in ports:
    print(i, ' - ', p.device)
    i += 1

port = 8    # int(input('Введите номер COM-порта: '))
baudrate = 115200   # int(input('Введите скорость COM-порта: '))

while port > len(ports):
    print("Такого порта - НЕТ !")
    port = int(input('Введите номер COM-порта: '))

print(ports[port - 1].device)

try:
    ser = serial.Serial(ports[port - 1].device, baudrate=baudrate)
    print("Serial connection established.")

    while True:
        line = ser.readline().decode().strip()

        if line:
            print(line)

except serial.SerialException as se:
    print("Serial port error:", str(se))

except KeyboardInterrupt:
    pass

finally:
    if ser.is_open:
        ser.close()
        print("Serial connection closed.")
```