''' Purpose: introduce lists
'''

# this is being created on the flyyyyyyy

reply = input('Enter a line of text: ') # if we respond with Wubba lubba dub dub!

# split reply into individual words...but we don't know how many words are being entered!!!!
# how do???
words = reply.split() # ignores leading and trailing whitespace
# officially, split returns a list

print(reply) # reply is the string 'Wubba lubba dub dub!'
print(words) # words is a list ['Wubba', 'lubba', 'dub', 'dub!']

# [] is the empty list

# Enter a line of text: 1 3 5 7 9
# 1 3 5 7 9
# ['1', '3', '5', '7', '9']  this is a list of STRINGS

for w in words: # words is a sequence; w in words represents each element in the list words
    # w is the iterator; each time the loop repeats, w changes because we are going through each element in the list
    print( ' ', w )

# for word in words:
#     print(word)

reply2 = input('Enter a list of numbers: ')
numbers = reply2.split()
# we want to convert each number in numbers into a int
# numbers = int(numbers)  # numbers is a list...a list is not a single value, but a SEQUENCE of values
# print(numbers)
n = len(numbers) # the number of elements in numbers
for i in range(0, n):
    nbr = numbers[i]  # numbers[i] takes the value from that index, i, of the list numbers
    nbr = int(nbr)    # nbr points to the same value as numbers[i], so we are converting (casting) nbr to an int
    numbers[i] = nbr  # the int version of nbr is being inserted back into the original list in the same index (spot)
print(numbers) # no quotes around each number, so that means each element is an int