TLE pls tell me the best way for it ->python

pastebin.com/5z58hpWF -> Python code
Can someone explain me why it doesn't work? (TLE)
There are any other faster solutions to check if number is prime?

Thanks for help ;)

Proof of my theory above/below: look at jhaanuj2108's code. It is terrible, but it uses a square root trick. He succeeded. almost NO optimizations and he still passed. Use the square root trick.

import java.util.Scanner;
class PrimeGenerator {
public static boolean isPrime(int no)
{
if(no==1)
return false;
int y=(int) Math.sqrt(no);
for(int j=2;j<=y;j++)
{
if(no%j==0)
return false;
}
return true;
}
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
int t=sc.nextInt();
for(int i=0;i<t;i++)
{
int beg=sc.nextInt();
int end=sc.nextInt();
for(int j=beg;j<=end;j++)
{
if(isPrime(j))
System.out.println(j);
}
System.out.println("");
}
}


}