## Lecture 2 - Input and Conditionals ##
# Michelle Szucs

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########## Getting user input ############

# Using input
# Remember that input will store numbers as ints or floats
myAge = input("What is your age? ")
friendAge = input("What is your friend's age? ")

# Using raw_input
# After receiving the input, you have to cast it to the
# correct type. This is called typecasting.
# You can uncomment the following lines (and comment the part
# with input) if you want to try the code this way.

#myAge = int(raw_input("What is your age? "))
#friendAge = int(raw_input("What is your friend's age? "))

# These print statements check whether the inputted values
# are integers. In the shell, you'll just see True or False
# when you run your code. That's because the whole statement
# is evaluated in the same way that we evaluate 3*5
print type(myAge) == int
print type(friendAge) == int

########## Branching if/else/elif statements #########

# First, we need to check that our variables are the correct
# type if we use input.
# Remember that these two statements evaluate to True or False.
# Therefore, the if statement can be simplified to:
# if True and True: (True)
# if True and False: (False)
# if False and True: (False)
# if False and False: (False)
if (type(myAge) == int) and (type(friendAge) == int):
    # Code at this level of indentation only executes
    # if the above if statement evaluates to True
    if myAge > friendAge:
        print "You're older."
        # You can add a lot more code at this level of
        # indentation that will only be executed if
        # myAge > friendAge. Try it!
    elif myAge < friendAge:
        print "You're younger."
    # You can string together multiple elif statements.
    # Each elif will only be executed if none of the previous
    # elif statements at the same level of indentation were
    # True but the current elif is True.
    else:
        print "You're the same age."
    # Make sure you consider all possible conditions before
    # writing a final else statement!

# If the first if statement wasn't satisfied, we know the user
# inputted something other than an integer - it's a good idea
# to have a sort of error message that explains why the code
# didn't run.
else:
    print "Invalid input"



"""(Three quotes can enclose multi-line comments).
Boolean comparators:
>
>=
<
<=
==
!=
and
or
not
"""