Module 4 - Branching Control Structures

S4 - Number Guessing Game

Let's make a simple game - The computer will come up with a secret number, and the user will try to guess what it is. This will require us to use an "if" and "else" statement to decide whether or not the user guessed correctly.  I'll provide a lot of the code, and challenge you to fill in the most important part: The part that decides whether the user has guessed right or wrong.

Remember, there are two different operators that look very similar:

The = operator, called the "assignment" operator, actually assigns a value to a variable, much like putting something in a container. For example, if we code the following:

x = 5

We are telling Python that the variable x is now equal to 5. To put it another way, it's like putting the number 5 in a container labeled "x". The variable x will stay equal to 5 until we change it to something else.
An operator that might feel very similar to this is the "comparison" operator, which is written using two "equals" signs, like this: == 
Where the assignment operator tells a variable it is equal to something, the comparison operator asks, "are these two things equal?". The result of a comparison is always either "True" or "False". 

Here are a few examples in code:

2+1 == 3
# This is True, because "2+1" is equal to "3"
"three" == 3
# This is False, because even though they are conceptually similar, 
# Python doesn't understand anything other than the fact 
# that a string can't equal an int.
x * 6 == x * 3 * 2
# This will be True, no matter the value of x, 
# because one side will always be equal to the other side.
"Bill" == "bill"
# Even though they are the same letters on each side, this is False because Python 
# sees uppercase and lowercase letters as different.

So now that we have an idea of how the comparison operators work, let's look again at the way an if statement would use those.  An if statement does something if the expression part of the statement is equal to True.  Look at the following:

x = 5
if (x == 5):
     print("X is equal to 5")

Since x is indeed equal to 5, Python will execute (or run) the code that is directly indented below the if statement.  When you run this code, Python will print "X is equal to 5".  Try it out - I'll wait here. You can do this in PyCharm or in online-python.com -- Either will work.(NOTE: indent the line starting with "print" by one tab)

Now, try changing the x = 5 line to the following:

x = 10

Notice that when you run the code, nothing happens. Well, nothing you can see, anyway. What happens is that Python sets x to equal 10.  Then, Python asks whether x is equal to 5.  Since that is False, then Python just skips the indented code block, and the program ends without printing anything.

What if we wanted to print something if the if statement is true, but print something different if it was false? We can do that!  The solution is to add an "else" statement, like this:

x = 10

if (x == 5):
     print("X is equal to 5")
else:
     print("X is NOT equal to 5")

In the case above, Python will print "X is NOT equal to 5", because x is 10 and the if statement is False.

So, now for the challenge…

Use what you've learned about if and else to finish the following code. In it, the computer will generate a random number, and the user will have a chance to enter a guess as to what the number might be. Your job is to tell the user whether their number is the same as the computer's secret number or not.

Here is your starter code:

import random
# the above line tells Python that we want to
# import and use the random module.

intSecretNumber = random.randint(1,10)
# The line above uses the random module's randint (random integer) 
# function to generate a random int between 1 and 10.
# The random number is assigned to the variable "intSecretNumber"

intUserGuess = int(input("Guess a number between 1 and 10: "))
# this line of code asks the user to input a number between 1 and 10, 
# converts their input string to an int, 
# and then assigns it to "intUSerGuess".

For a BONUS CHALLENGE, if the user guesses wrong you can tell them what the secret number was after they miss.

A4 - More Advanced Calculator

# Show the UI
        print("#" * 80)
        print("#" * 9, " " * 60, "#"*9)
        print("#" * 9, "Advanced Calculator".center(60), "#" * 9)
        print("#" * 9, " " * 60, "#"*9)
        print("#" * 80)
        # Welcome the user
        
        # Show the menu options
        
        # Get input from the user.
        
        # if the user chooses 1, do C to F
        
        # ask for degrees in C
        
        # do the calculation
        
        # if the user chooses 2, do F to C
        
        # if the user enters anything else, give an error message