'''lecture_18_nested_loops.py
Demonstrate using nested lists
Oliver W. Layton
CS 151: Computational Thinking: Visual Media
Fall 2020
'''


'''
Visiting every item in a list with sublists
'''
# How can we access and replace every item in `digits`
# with 10 times the number?
digits = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]

# What is len(digits)?
print(len(digits))

# If we loop thru, what type of data is digits[i]?
for i in range(len(digits)):
    print(digits[i])

# To visit each int, as we loop through the list,
# let's start looping thru the sublist and print each item.
for i in range(len(digits)):
    # inside "i" loop over sublists. Now we loop thru the SUBLIST digits[i] and get single items out
    for j in range(len(digits[i])):
        print(digits[i][j])

# Now let's tackle the problem of replacing each number with 10 times
# the amount.

# What values do `i` and `j` take on while iterating thru the nested loop?
# Let's print the see