Can't send data from python to arduino

Hi guys, please help me.

I expect blinking.

This code works good:

void setup() {
pinMode(9, OUTPUT);
}
void loop() {
digitalWrite(9, HIGH);   
delay(1000);                     
digitalWrite(9, LOW);  
delay(1000);                
}

but with python pyserial doesn't work:

I have problem on:
print ArduinoSerial.readline()
(code is freezing)
so it look's like I can't read data from arduino.
But PORT is correct - I am sure. When I start to run script I see on arduiono board that it receives data.(It is blinking during a second)

OS MAC.
Python 2.7:

import serial  
import time  

ArduinoSerial = serial.Serial("/dev/cu.wchusbserial1410", 9600)
time.sleep(2)

print ArduinoSerial.readline()  


print ("Enter 1 to turn ON LED and 0 to turn OFF LED")

while 1:  

 var = raw_input()  # get input from user
 print "you entered", var  # print the intput for confirmation

 if (var == '1'):  # if the value is 1
 ArduinoSerial.write('1')  # send 1
 print ("LED turned ON")
 time.sleep(3)

 if (var == '0'):  # if the value is 0
 ArduinoSerial.write('0')  # send 0
 print ("LED turned OFF")
 time.sleep(3)

There is nothing in your Arduino program that sends or reads serial data

When I start to run script I see on arduiono board that it receives data.(It is blinking during a second)

That is because it is running a program that blinks the LED whether or not anything is received.

This Python - Arduino demo may help get you started.

...R