Contents

  1. binaryToDecimal.py
  2. oldmac.py
  3. testingBinaryToDecimal.py

binaryToDecimal.py 1/3

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# Converts a binary number into a decimal
# Modify to verify that the inputted number is valid.
# Added test functions that programmatically test if the function is behaving
# appropriately.
# By CSCI111

import sys

def main():
    # Read in the binary number as a string -- why?
    num = input("Enter the binary #: ")
    
    # --------- Validate the user input ----------
    if not isBinary(num):
        print(num, "is not a valid binary number.  Please try again.")
        sys.exit()
        
    decVal = binaryToDecimal(num)
    
    print("The decimal value for", num, "is", decVal)


def binaryToDecimal(binnum):
    """
    Converts the binary number to a decimal number
    Precondition: binary, a string that is a binary number
    Postcondition: returns the decimal value of the binary number
    """
    # accumulate the decimal value in this variable
    decVal = 0
    
    # go through the positions in the string
    for pos in range(len(binnum)):
        # num[pos] is a string; need to convert to an int
        bit = int(binnum[pos])
        # calculate which "place" the current bit is at
        place = 2**(len(binnum)-pos-1)
        # add to the decimal value
        decVal += place * bit
    return decVal

    
def isBinary(candidate):
    """
    Precondition: candidate is a string
    Postcondition: returns True iff candidate is a valid binary string
    """
    # check that it has all digits (no letters)
    if not candidate.isdigit():
        return False
     
    # Make sure that the inputted number only contains 0s and 1s
    for digit in candidate:
        if digit != "0" and digit != "1":
            return False
    return True


oldmac.py 2/3

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# Print out verses of the song Old MacDonald
# Sara Sprenkle

BEGIN_END = "Old McDonald had a farm"
EIEIO = ", E-I-E-I-O"

def main():
    # call the verse function to print out a verse
    printVerse("dog", "ruff")
    printVerse("duck", "quack")
    
    animal_type = "cow"
    animal_sound = "moo"
    
    printVerse(animal_type, animal_sound)
    

def printVerse(animal, sound):
    """
    prints a verse of Old MacDonald, plugging in the animal and sound
    parameters (which are strings), as appropriate.
    """
    print(BEGIN_END + EIEIO)
    print("And on that farm he had a " + animal + EIEIO)
    print("With a " + sound + ", " + sound + " here")
    print("And a " + sound + ", " + sound + " there")
    print("Here a", sound)
    print("There a", sound)
    print("Everywhere a " + sound + ", " + sound)
    print(BEGIN_END + EIEIO)
    print()

if __name__ == '__main__':
    main()
#main()

testingBinaryToDecimal.py 3/3

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# Demonstrates how we can include other's code in our code
# by importing them as modules.

from binaryToDecimal import *

def testIsBinary():
    """
    Test the isBinary function.
    Displays the correctness or incorrectness of the function.
    Does not return anything.
    """
    
    # ----------- Test where the result should be True ---------

    testBinaryTrue = ["0", "1", "10", "1001", "10000"]
    
    for test in testBinaryTrue:
        result = isBinary(test)
        if result:
            print(test, "successfully identified as binary")
        else:
            print("**ERROR! **", test, "considered not binary")
    
    # ----------- Test where the result should be False ---------
    testBinaryFalse = ["a", "3", "-100", "123"]
    
    for test in testBinaryFalse:
        result = isBinary(test)
        if not result:
            print(test, "successfully identified as not binary")
        else:
            print("**ERROR! **", test, "considered binary")
    
    # ------------ Alternatively, have a list of inputs and expected ----
    # Question: How difficult is it to verify additional test cases?
    inputs = [ "0", "1", "10", "1001", "10000", "a", "3", "-100", "123"]
    expectedResults = [ True, True, True, True, True, False, False, False, False]
    for pos in range(len(inputs)):
        testInput = inputs[pos]
        if isBinary(testInput) != expectedResults[pos]:
            print("Error on isBinary(", testInput, ")")
            print("Expected", expectedResults[pos], "but got", isBinary(testInput))
    

def testBinaryToDecimal():
    """Test the binaryToDecimal function.  
        Displays the correctness or incorrectness of the function.
        Nothing is returned."""
        
    paramInputs = ["0", "1", "10", "1001", "10000", "1101", "10110"]
    expectedResults = [ 0, 1, 2, 9, 16, 13, 22]
    for index in range(len(paramInputs)):
        paramInput = paramInputs[index]
        expectedResult = expectedResults[index]
        actualResult = binaryToDecimal(paramInput) 
        if actualResult != expectedResult:
            print("**ERROR! **", paramInput, "should be", expectedResult)
            print("Instead, got", actualResult)
        else:
            print("Success on binary to decimal conversion for", paramInput, "-->", actualResult)
            
            
testIsBinary()
testBinaryToDecimal()            

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