19. 99 Bottles (+20 XP)

# Squares

On May 6th, 1949, EDSAC, an early electronic stored-program computer, ran its first programs at the University of Cambridge.

It calculated and printed out a list of squares:

          
            0   0
            1   1
            2   4
            3   9
            4   16
            5   25
            6   36
            7   49
            8   64
            9   81            
          
        

On the left, you got all the single-digit numbers from 0 to 9. On the right are their squares. For example, in the last row, 9 * 9 = 81.

This can be done in Python using string concatenation:

          
          # String concatenation

          for i in range(5):
            print("The square of " + i + " is " + i*i)
          
        

The output would look like:

          
          The square of 0 is 0
          The square of 1 is 1
          The square of 2 is 4
          The square of 3 is 9
          The square of 4 is 16
          
        

# String Interpolation

Let's learn a new tool that's very similar to string concatenation, before continuing onto the challenge.

String interpolation is a process of substituting values of variables into placeholders in a string.

For instance, if you have a template for saying hello to a person in an email like "Hi {name}, nice to meet you!", you would like to replace the placeholder {name} with an actual name. This is string interpolation.

The above program can be recreated using string interpolation using the {} sign:

          
          # String interpolation

          for i in range(5):
            print(f"The square of {i} is {i*i}")
          
        

Notice the f prefix before the quotes. This was introduced in the new Python 3.6 version.

# Instructions

"99 Bottles of Beer" is an old song that annoying kids sang on road trips to pass time.

Create a 99_bottles.py program and use a for loop and a range() function to print out all the verses of "99 Bottles of Beer".

And don't forget to use string interpolation!