Serial connect with custom end of line character

PySerialCustomeEndLine

import serial,time

ser = serial.Serial('COM1')
ser.write("$$\r\n")

def readline():
    eol = b'\r'
    leneol = len(eol)
    line = bytearray()
    while True:
        c = ser.read(1)
        if c:
            if ord(c) != 17 and c != 13:
                line += c
            if line[-leneol:] == eol:
                break
        else:
            break
    return bytes(line)

time.sleep(0.1)
print(readline())

while ser.inWaiting():
    print(readline())
    time.sleep(0.01)

ser.close()