The purpose of this lab is to gain experience with looping constructs.

Part I.  Testing Loops

• In a file loops.py, define one function per example of iteration given below, so four functions total.
• Define a main function that calls each of your new functions, one after the other.
• Call main

Number 1: call this function sumVals

    print("This function sums three values")
    sum = 0

    for i in range(3):
        x = int(input("Next value to sum, please: "))
        sum = sum + x 
     
    print("Sum = ", sum)

Number 2: call this function times_table

    for i in range(1,5):
        for j in range(0, 11, 2):
            print(i, '*', j, '=', i*j)

Number 3: call this function debits

    bankBalance = 500.0
    print("Your balance is $", bankBalance)
    
    while bankBalance > 0:
       # user enters positive values representing checkcard purchases
       checkAmt = float(input("Debit Amt? "))
       print(" -  $",checkAmt)
       bankBalance = bankBalance - checkAmt

    print("You are overdrawn by $", -bankBalance)

Number 4: call this function getting_smaller

xm = 10.0
while xm < 100.0:
   print(xm, "is less than 100")
   xm = xm * 0.5

Run each function and record the results of each run. For the two that request user input, try them with input of your own devising but record what values you input along with the results. If the result is an infinite loop - record that. Remember that typing <Ctrl-C> will interrupt an out-of-control program.

Write up the results (cleanly, legibly, and well labeled) for turn in, either on paper on in a text editor.

Now, make the following changes to the functions sumVals and debits:

• For sumVals, add a parameter vals; instead of adding up three values, the function will now use vals to determine how many numbers to sum.
  
• Be sure to change the first print to reflect the new behavior
• In main, call sumVals with a number of your choice
• For debits, change bankBalance from a regular variable to a parameter, so we can give it different balances
• In main, call debits with a new balance of your choice
• Add a docstring and function signature to each function (note, if a function takes no arguments and returns no value, its signature is None -> None)
• Remove the call to getting_smaller

Demonstrate!

Part II. Drawing using Iteration

Switch driver and observer. Make a new program file for the following problem. Use at least one loop in your program; decide among yourselves if a for loop or a while loop would be most appropriate. All your program code can go in the main() function.

1. AlmostBullseye
   
   Write a program called AlmostBullseye.py that draws a "lopsided" bullseye in a window. The biggest circle should be 100 pixels in diameter, while the smallest circle should be 20 pixels in diameter.  Each circle in between should be 20 pixels smaller in diameter than the circle surrounding it. The circles will all have the same upper left-hand corners at location (10, 10). Use a loop - each loop iteration draws the next smaller circle.
   
   

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