Please use python to code

Problem 2 Write a function num_primes (n) that returns the number of primes that are less than or equal to n. For instance num_primes (5) should return 3, since 2,3,5 are the primes that are less than or equal to 5. Do not use any bulit-in functions that have to do with primes (you are welcome to reuse the primality test function you wrote for a previous homework). Use it compute the ratio num_primes (n) for n = 10, 102, ..., 10%. Plot these ratios using the built-in list plot command (you will need to look up the syntax, since we haven't covered this). How do you think this ratio behaves as n