Arduino Uno , Keyboard Lib. , Serial Communication and Python

Hello guys.
I found out that there is no keyboard library for arduino uno.
I need to make arduino push a keyboard letter when i push a button on arduino.
So i thought if i click a button on arduino.
Send "clicked" string from arduino to pc.
Then python script
then click a letter on keyboard.
But i couldnt make that.

int buttonPin = 12;
void setup() {
// put your setup code here, to run once:
pinMode(buttonPin,INPUT_PULLUP);
Serial.begin(9600);
}

void loop() {
// put your main code here, to run repeatedly:
int buttonValue = digitalRead(buttonPin);
if (buttonValue == 0){
//this means button pushed
Serial.println(buttonValue);
}
//if (buttonValue == 1){
else{
//this means buton bırakıldı amk
//Serial.write("Break" + buttonValue);
}
}

-- coding=utf-8 --

import serial
ser = serial.Serial("/dev/ttyUSB0",9600)
print ser
val = ser.readline()
print (val)
if (val == "0"):
print("BINGO !")

Serial.println(buttonValue);

The ln in println means to send the data and a carriage return and line feed. So what is actually sent is "0\r\n" or "1\r\n" (0x30 0x0d 0x0a or 0x31 0x0d 0x0a).

OMG , how didnt i realized it.Thank you bro.