Quote:
reads the grades of 3 students from the 4 months of the cycle
You might want to use
Improve question to outline from what/where and how the data is going to be read - ie file, csv/tsv or keyboard
For now, I suggest you look at Python arrays, using 'for' to iterate them for example .. you could also use a simple 'driver' to get started, reading the number of elements and the elements themselves from the keyboard as in
# creating an empty list
lst = []
# number of elements as input
n = int(input("Enter number of elements : "))
# iterating till the range
for i in range(0, n):
ele = int(input())
lst.append(ele) # adding the element
print(lst)
that gives you an array (lst) of 'string', it's simple enough to declare and add the data as integers, but that would be doing your homework for you.