(a) Read in data from a file on internet using the following commands
import urllib
f=urllib.urlopen("http://web.njit.edu/~zhiwei/BNFO135/dna.fasta")
data=f.readlines()

The two DNA sequences on the 2nd and 4th line have the same length.
(1) Give Python commands to compute how many C in the 2nd DNA 
sequence (4th line)
(2) Give Python commands to compute how many dna bases at the same position
in the first 5 characters are equal in these two sequences.

(b) Write a Python script that asks the user to enter a DNA sequence 
and prints "Your input has non-A characters." just once if the sequence
contains any letter  other than A. Otherwise the program should output 
"Your input are all As." just once. For example if the user types
in ACC the program should output should be "Your input has non-A characters.".
However, if the user types AAA then the output should be 
"Your input are  all As." 

(c) Given an array length 1 or more of ints, return the largest value in the array.
my_max([10, 3, 5, 6]) -> 10
my_max([7, 2, 11]) -> 11
my_max([2, 10, 7, 2, 19]) -> 19

def my_max(nums):