Computer Number Systems – Part 1

Prof. Joseph J. LaViola Number System Resources

Since binary numbers representing moderate values quickly become rather lengthy, bases eight (octal) and sixteen (hexadecimal) are frequently used as short-hand. Octal numbers group binary numbers in bunches of 3 digits and convert the triplet to a single digit between 0 and 7, inclusive.

Some online help on binary numbers

Classwork:Do the rest of the parts for each exercise.

Homework:
Work on Tic Tac Toe project.

Computer Number Systems – Part 2

All computers – from large mainframes to hand-held micros – ultimately can do one thing: detect whether an electrical signal is “on” or “off”. Computer programs in BASIC and Pascal are converted by various pieces of systems software into sequences of bits (Binary digITs) which correspond to sequences of on/off (equivalently TRUE/FALSE or 1/0) signals. Proficiency in the binary number system is essential to understanding how a computer works.

The Decimal Number System

The Binary Number System

Convert a Binary Number to Decimal Number

The Hexadecimal Number System

The Octal Number System

Converting between different Number Systems.

Prof. Joseph J. LaViola Number System Resources

Since binary numbers representing moderate values quickly become rather lengthy, bases eight (octal) and sixteen (hexadecimal) are frequently used as short-hand. Octal numbers group binary numbers in bunches of 3 digits and convert the triplet to a single digit between 0 and 7, inclusive.

Some online help on binary numbers

Classwork:Do parts a and b for each exercise.

Work on Tic Tac Toe project.

working with lists

Classwork:
Write a new program, ListClwk_YI.py with the work develop in class.
1. Create a list, aList of 100 integers from 1 through 100.

Some tricks you should know:

total = 0
for i in range( len( aList ) ):
   total += aList[i]
print ("the sum of all items in the list is ", total)

total = 0
for item in aList:
   total += item
print ("the sum of all items in the list is ", total)

print ("the sum of all items in the list is ", sum(aList))

2. Create an empty list and adds to the end of the list 100 random integers from 10 to 500
3. Print the list in 10 rows by 10 columns format. Make sure the columns are lined up.
4. Count the number of integers that are even and odd and displays the values with a message.

python’s basic concepts in lists
Write a python program list_basics_YI.py

1. Creating a list.
2. add elements to a list
3. access a list’s values by iteration
4. access a list’s values by index
5. modify elements in a list
6. add all elements in a list
7. assign 100 random integer numbers between 1 and 100 to a new empty list, new_list

# 1. Creating a list.

a_list = []    # create empty list

# 2. add elements to a list
for number in range( 1, 11 ):
   a_list += [ number ]

print ("The values of a_list are:", a_list )  

# 3. access a list's values by iteration
print ("\nAccessing values by iteration:")

for item in a_list:
   print (item,end='')
print("\n")

# 4. access a list's values by index
print ("\nAccessing values by index:")
print ("Subscript   Value")

for i in range( len( a_list ) ):
   print ("%9d %7d" % ( i, a_list[ i ] ))

# 5. modify elements in a list
print ("\nModifying a list value...")
print ("Value of aList before modification:", a_list)
a_list[ 0 ] = -100   
a_list[ -3 ] = 19
print ("Value of aList after modification:", a_list)

# 6. add all elements in a list
total = 0
for i in range( len( a_list ) ):
   total += a_list[i]
print ("the sum of all items in the list is ", total)


# 7. assign random integer numbers between 1 and 100 to a new empty list, new_list

Required Submission
1. Copy and paste the programs in the Text Entry tab.
2. Submit the list_basics_YI.py or the repl.it link.
NOTE: Documentation
Header:

a) Assignment description ( you can copy and paste the assignment itself)
b) Author’s name
c) Language and version
d) Date of completion
Input/Output:
Input(If any) and output for each part.

Complete this assignment.

###################################################################
# Description: improve this program by using functions 
# Mrs. Elia
# 10/7
# python 3.9
#
###################################################################
aName = input("Hi! What is your name? ")
print "Hello ",aName, "! I hope you are enjoying your day!"

##>>> 
##Hi! What is your name? grace
##Hello grace! I hope you are enjoying your day!
##>>> 

Here is an outline of the changes:

#from
aName = input("Hi! What is your name? ")
print "Hello ",aName, "! I hope you are enjoying your day!"

# to functional programming
def hello(aName): # it prompts the user for a name
                  # it prints a message with the name

def main():       # it calls the only one function

main()  # execute by calling it

Read this article: Fostering Tech Talents in School. All of it.

Constructor Functions and the type() function: Functions that have the same name as their data type and create objects or values of this data type are called constructor functions. How do you find the value’s data type?

pygame.PixelArray Data Type and the PixelArray() constructor function.

Python Variable scopes

#####################################################################
#  YI_MoreOnScopes1.py
#  Mrs. Elia
#  12/17/14
#  Local and global variables
#####################################################################
#
#  Definitions
#
#####################################################################

def intro():
    message = ' Welcome to my world '
    switch = 'off'
    print(switch)


def closing():
    switch = 'neither'
    print(switch)

## Main
switch = 'on'
print(switch)
intro()
closing()
print(switch)

Classwork:
1. Change the definitions so each of them reassign the value of the global variable switch.
2. Remove the print statement in each of the definitions but print the value of the global variable switch after each definition call.
This is what it should look like:

# Main
switch = 'on'
print(switch)
intro()
...
print(switch)
closing()
...
print(switch)

Output:
on
off
neither
 
Homework:
The output should be: It is a wonderful day. Fix the problem without removing the definitions and without adding print staments to the definitions.

#####################################################################
#  YI_MoreOnScopes2.py
#  Mrs. Elia
#  12/15/2014
#  Local and global variables
#
#####################################################################
#  Definitions
#####################################################################

def intro():
    word1 += "is a"
    word2 = "wonderful"
    return word2

def closing():
    word4 = "day."

## Main
word1 = "It"
message = word1
message = intro()
message = closing()
print(message)


# The output should be: It is a wonderful day.
# Fix the problem without removing the definitions and
# without adding print staments to the definitions.

The output should be:
It is a wonderful day.

A little help with the spaces in the phrase:

phrase = "have a good day"
phrase = phrase.replace(' ','-') # replace space with dash
newphrase = ''

blanks = '_ ' * len(phrase) # underscore plus space

for i in range(len(phrase)):
    newphrase += phrase[i] +' ' # add a space to each letter to match
                                # the underscores plus space


for i in range(len(blanks)):
    if newphrase[i] == '-':
        blanks = blanks[:i] + '-' + blanks[i+1:] # replace the underscore
                                              # with the corresponding dash

print(newphrase)
print(blanks)


##>>> 
##h a v e - a - g o o d - d a y 
##_ _ _ _ - _ - _ _ _ _ - _ _ _ 
##>>> 

Classwork:
Scope: Local

#####################################
#      NO Imports
#####################################

#####################################
#  G.Elia
#  Mail Order application with functions
#  Python 3.5
#  today's date
#####################################

print("This is an order form for a mail-order house.")

#####################################
#      Functions' Definitions
#####################################

def initializeTotal():
    totalinit = float(0)
    return totalinit

def productPrompt():
    product = int(input("Product number? "))
    return product

def quantityPrompt(product):
    quantity = int(input("Quantity? "))
    if product == 1:
        subTotal = quantity * 2.98
    elif product == 2:
        subTotal = quantity * 4.50
    elif product == 3:
        subTotal = quantity * 9.98
    elif product == 4:
        subTotal = quantity * 4.49
    elif product == 5:
        subTotal = quantity * 6.87
    return subTotal

def final (total):
    print("Total Price:",total)

    
##############################################
# main - Driver: control the flow of execution
##############################################

yesNo = 'y'
totalInit = initializeTotal()
while yesNo == 'y':
    product = productPrompt()
    totalInit += quantityPrompt(product)
    yesNo = input("Do you want to continue? (y/n) ")
final(totalInit)

## input/output
##>>> 
##This is an order form for a mail-order house.
##Product number? 1
##Quantity? 2
##Do you want to continue? (y/n) y
##Product number? 2
##Quantity? 3
##Do you want to continue? (y/n) n
##Total Price: 19.46
##>>> 

List Applications

# Creating a histogram from a list of values.

values = []   # a list of values

# input 10 values from user
print ("Enter 10 integers:")

for i in range( 10 ):
   newValue = int( input( "Enter integer %d: " % ( i + 1 ) ) )
   values += [ newValue ]

# create histogram
print ("\nCreating a histogram from values:")
print ("%s %10s %10s" % ( "Element", "Value", "Histogram" ))

for i in range( len( values ) ):
   print ("%7d %10d  %s" % ( i+1, values[ i ], "*" * values[ i ] ))

ClassworkHomework:
Exercise 1: NoDuplicates_YI.py
Use a list to solve the following problem: Read in 20 numbers. As each number is read, print it only if it is not a duplicate of a number already read.
Make it an interactive program:
1. A message should be displayed when the user enters a number that has already entered as input.
2. As a way to validate no repeats it prints back the number.

Sample Output:
Enter a number: 2
2
Enter a number: 4
4
Enter a number: 5
5
Enter a number: 2
2 is a duplicate
Enter a number: 10
10
…

Exercise 2: StudentPoll_YI.py
Write a python program StudentPoll_YI.py that uses a list to summarize data collected in a survey. Consider the following problem statement:

Sixteen students were asked to rate on a scale of 1 to 10 the quality of the food in the student cafeteria, with 1 being “awful” and 10 being “excellent”. Place the 16 responses in a list and determine the frequency of each rating.

Randomly assign 16 numbers between 1 and 10 to a list, survey, and use this list as an index of another list, ranking, to keep track of the count of the responses.
Create a histogram with the ranking data.

A little help…

ranking = [0,0,0,0,0,0,0,0,0,0,0]
survey = [1,5,3,4,1,1,1,2,1,2,1,3,4,5,1,7]

Do not  use "if's" statements. Instead use the following:

       ranking[ survey[ i ]  ] + = 1

Exercise 3: ScoreKeeper_YI.py
You are a score keeper for 20 ice hockey players. Implement the code to keep track of their scores using a list. Program accepts integers as input and it is called ScoreKeeper_YI.py. Simulate a game by entering a good number of scores.

Sample output:

>>> 
... the game is on!!!
what player scored a goal? 3
what player scored a goal? 5
what player scored a goal? 3
what player scored a goal? 3
what player scored a goal? 5
still game on?y/n y
what player scored a goal? 5
what player scored a goal? 5
what player scored a goal? 5
what player scored a goal? 4
what player scored a goal? 6
still game on?y/n y
what player scored a goal? 5
what player scored a goal? 5
what player scored a goal? 7
what player scored a goal? 8
what player scored a goal? 1
still game on?y/n y
what player scored a goal? 5
what player scored a goal? 5
what player scored a goal? 3
what player scored a goal? 2
what player scored a goal? 5
still game on?y/n n

Creating a histogram from players:
Player      Goals  Histogram
      1          1  *
      2          1  *
      3          4  ****
      4          1  *
      5         10  **********
      6          1  *
      7          1  *
      8          1  *
      9          0  
     10          0  
     11          0  
     12          0  
     13          0  

Exercise 4: BingoNumKeeper_YI.py
You are in charge of keeping track of the numbers that are called out in a Bingo game. Using a list implement the code to keep track of the numbers. The numbers will be called until the board is completely filled up. You can think of this simulation as if the balls are replaced back for drawing again. In this program use the random feature to simulate turning the spherical basket with all the balls inside. It is similar to the game of Bingo but not quite. At the end of the program print the number of times a random number was called with a meaningful message. Name your program BingoNumKeeper_YI.py

Classwork:
Open a new file, YI_PythonSyntax.py
Include the output and some comments from the following code:

# don't forget the header and comments

import random

# returning a list
x = 2
y = 3


def returnAList(a,b):
    a += 2
    b += 3
    return [a,b]

# Main
xyList = returnAList(x,y)

print(xyList)
print(xyList[0])
print(xyList[1])

# print either 0 or 1
for i in range(10):
    print(random.randint(0, 1),end = ' ')

# print the first letter
print()

print('yes'.lower().startswith('y'))

# adding items to any list
anyList = []
anyList.append(2)
anyList.append(3)

print(anyList)

sentence = 'it is a wonderful day'
sentence = sentence.split()
print(sentence)

sentence = ' '.join(sentence)
print(sentence)

# random choice
spaces = '1 2 3 4 5 6 7 8 9'.split()
print(spaces)
print(random.choice(spaces))
print(random.choice(spaces))
print(random.choice(spaces))

# what does this print?
print(None)

Classwork:Tic-Tac-Toe.
Write an algorithm to play Tic-Tac-Toe. (Use pseudocode)
You are allowed to use the following functions from Al Sweigart’s program but your don’t have to:
isWinner(bo, le)
drawBoard(board)
isBoardFull(board)
getPlayerMove(board)
The rest must be implemented with your original and creative algorithm.

NOTE: this is a “what if” type of program. Think of all the moves ahead at each step. You can use as many “if’s” as you want!!
Keeping in mind the different locations in the board:

Visit edmodo.com and answer these questions that could help you put together your algorithm. Remember it is your algorithm!

1. Before you commit to a move, what two things should your program check for?
2. What is the best spot on the board to start or to take the next safe move in the game?
3. What is the next best spot?
4. What is left when all the good spots are gone?
5. How many moves does it take to win, tie or lose a game of Tic Tac Toe? Best case, worse case and in an average case.

Make sure your algorithm addresses all these questions otherwise it would not be a good tool to help you write a smart AI program.

Programming Design:
1. What do you think is the best way to hold information about the space selected? Would you have 9 variables or a list?
2. Would you use while, for loop or both?

Homework:
Write first draft for TTT.py using pseudocode

NOTE: TO MAKE IT MORE INTERESTING AND INVITING TO THE PLAYER, MAKE THE FIRST COMPUTER MOVE RANDOM. However, it should be intelligent once the game is on.

NOTE: IF YOU TURNED IN THE MAIL ORDER ASSIGNMENT AND DIDN’T GET A GRADE, LOOK FOR MY COMMENT ON THAT POST.

Classwork:
Complete missing assignments before you move on
Learning
Variable Scope
Global Scope and Local Scope
Parameters
Where the Program Really Begins: MAIN

Start reading the next chapter:

Download the program and play with it. Pay special attention to details

Hangman Game

def getGuess(alreadyGuessed):
    # Returns the letter the player entered. This function makes sure the player entered a single letter, and not something else.
    while True:
        print('Guess a letter.')
        guess = input()
        guess = guess.lower()
        if len(guess) != 1:
            print('Please enter a single letter.')
        elif guess in alreadyGuessed:
            print('You have already guessed that letter. Choose again.')
        elif guess not in 'abcdefghijklmnopqrstuvwxyz':
            print('Please enter a LETTER.')
        else:
            return guess

missedLetters = ''
correctLetters = ''
secretWord = getRandomWord(words)
gameIsDone = False

while True:
    displayBoard(HANGMANPICS, missedLetters, correctLetters, secretWord)

    # Let the player type in a letter.
    guess = getGuess(missedLetters + correctLetters)

    if guess in secretWord:
        correctLetters = correctLetters + guess

        # Check if the player has won
        foundAllLetters = True
        for i in range(len(secretWord)):
            if secretWord[i] not in correctLetters:
                foundAllLetters = False
                break
        if foundAllLetters:
            print('Yes! The secret word is "' + secretWord + '"! You have won!')
            gameIsDone = True
    else:
        missedLetters = missedLetters + guess

        # Check if player has guessed too many times and lost
        if len(missedLetters) == len(HANGMANPICS) - 1:
            displayBoard(HANGMANPICS, missedLetters, correctLetters, secretWord)
            print('You have run out of guesses!\nAfter ' + str(len(missedLetters)) + ' missed guesses and ' + str(len(correctLetters)) + ' correct guesses, the word was "' + secretWord + '"')
            gameIsDone = True

    # Ask the player if they want to play again (but only if the game is done).
    if gameIsDone:
        if playAgain():
            missedLetters = ''
            correctLetters = ''
            gameIsDone = False
            secretWord = getRandomWord(words)
        else:
            break