Contents
- binaryToDecimal.test.py
- descendSort.py
- oldmac.py
- pick4num_wfunctions.py
- swap.py
binaryToDecimal.test.py 1/5
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# Converts a binary number into a decimal
# Modify to verify that the inputted number is valid.
# 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(binary[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
def testIsBinary():
"""
Test the isBinary function.
Displays the correctness or incorrectness of the function.
Does not return anything.
"""
testBinaryTrue = ["10", "0", "0000", "01", "1000010"]
for test in testBinaryTrue:
result = isBinary(test)
if result:
print(test, "successfully identified as binary")
else:
print("**ERROR! **", test, "considered not binary")
testBinaryFalse = ["10a", "0000z", "1O", "O"]
for test in testBinaryFalse:
result = isBinary(test)
if not result:
print(test, "successfully identified as not binary")
else:
print("**ERROR! **", test, "considered binary")
def testBinaryToDecimal():
"""Test the binaryToDecimal function.
Displays the correctness or incorrectness of the function.
Nothing is returned."""
testInput = "10"
expectedResult = 2
actualResult = binaryToDecimal(testInput)
if actualResult != expectedResult:
print("**ERROR! **", testInput, "should be", expectedResult)
print("Instead, got", actualResult)
else:
print("Success on binary to decimal for", testInput, "-->", actualResult)
testIsBinary()
testBinaryToDecimal()
descendSort.py 2/5
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# Demonstrate passing lists to functions
# CSCI111
# this function tests the descend sort function
def main():
# test descendSort3Nums
list = [1,2,3]
descendSort3Nums(list)
print(list)
list = [0, 5, -3]
descendSort3Nums(list)
print(list)
list = [7,4,1]
descendSort3Nums(list)
print(list)
list = [-1, -1, -3]
descendSort3Nums(list)
print(list)
list = [-1, -5, -3]
descendSort3Nums(list)
print(list)
def descendSort3Nums(list3):
"""
Parameter: a list containing three numbers
Sorts the list in descending order
Note: does not return anything, no output
"""
if list3[1] > list3[0]:
# swap 'em
tmp = list3[0]
list3[0] = list3[1]
list3[1] = tmp
if list3[2] > list3[1]:
# swap 'em
tmp = list3[1]
list3[1] = list3[2]
list3[2] = tmp
if list3[1] > list3[0]:
# swap 'em
tmp = list3[0]
list3[0] = list3[1]
list3[1] = tmp
main()
oldmac.py 3/5
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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)
# QUESTION: What happens if main called function as
# printVerse("ruff", "dog")
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()
pick4num_wfunctions.py 4/5
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# Simulate Pick 4 lottery game - selecting ping pong balls at random
# Modified to figure out if the user entered the winning number
# By CSCI111
from random import *
import sys
# define constants that are easy to change so that our
# program is flexible
NUM_PICKS = 4
MIN_VALUE = 0
MAX_VALUE = 9
NUMFORMAT="####"
def main():
pickedNum = input("What is your pick? (Format: " + NUMFORMAT + ") ")
###### handle bad input ######
error = False
errorMessage = "Error:\n"
# Check that user enters a string that contains only numbers
if not pickedNum.isdigit():
errorMessage += "\tYour number must contain only numbers\n"
error = True
# User enters a number that is not four digits long
if len(pickedNum) != 4:
errorMessage += "\tYour number must contain four numbers"
error = True
if error:
print(errorMessage)
sys.exit()
winningNum = generateWinningNum()
print("The winning Pick 4 lottery number is ", winningNum)
print()
if winningNum == pickedNum:
print("Congratulations! You are very lucky and rich!")
print("We should be friends!")
else:
print("Sorry, you lost.")
def generateWinningNum(numNums=NUM_PICKS):
"""
generates a winning number based on constants defined for ...
returns a string of random numbers of length numNums;
default numNums is NUM_PICKS
"""
# Generate the random number
winNum = "" # start it as empty
for i in range(numNums):
# generate a random number
# add the random number to the previous random number
winNum += str(randint(MIN_VALUE,MAX_VALUE))
return winNum
main()
swap.py 5/5
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# Attempt at swapping two variables in a function
# FAIL! Swapping within a function won't work. :(
# Why? Only passing in *copies* of parameters, not the original variables
def swap( a, b):
tmp = a
a = b
b = tmp
print(a, b)
x = 5
y = 7
swap(x, y)
# at the end, y should be 5 and x should be 7
print("x =", x)
print("y =", y)
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