Continuing to prepare for the Battleship program

Classwork:

1. On a piece of paper decide in which edge you will place a 2 or 3-square ship.

2. Write a program, YI_4Edges.py to prompt the user for one of the edges locations on the 3 x 3 board and based on the user’s response write the code to find the ship and sink it.
– Use a list of three lists with 3 items each.
– Randomly select the edges where the program will place the ship.

Programming Project: The Wheel of Fortune
…

1. Understand the game thoroughly!
2. Draft your program using either pseudocode or flowchart
3. What can you take and adapt from the hangman.py program.
   

Hangman Game
More on lists:
What is the output from the next code snippet?

>>> wordIndex = 2
>>> print(wordIndex)
2
>>> print(['biology','chemistry','physics','algebra'][wordIndex])
physics
>>> 

Displaying the Board to the Player

def displayBoard(HANGMANPICS, missedLetters, correctLetters, secretWord):
    print(HANGMANPICS[len(missedLetters)])
    print()

    print('Missed letters:', end=' ')
    for letter in missedLetters:
        print(letter, end=' ')
    print()

    blanks = '_' * len(secretWord)

    for i in range(len(secretWord)): # replace blanks with correctly guessed letters
        if secretWord[i] in correctLetters:
            blanks = blanks[:i] + secretWord[i] + blanks[i+1:]

    for letter in blanks: # show the secret word with spaces in between each letter
        print(letter, end=' ')
    print()

Open a new window and create a python program, YI_displayBoard.py and copy the following code:

secretWord = 'apple'
blanks = '_' * len(secretWord)
correctLetters = 'l'
blanks

for i in range(len(secretWord)): # replace blanks with correctly guessed letters
    if secretWord[i] in correctLetters:
        blanks = blanks[:i] + secretWord[i] + blanks[i+1:]

for letter in blanks: # show the secret word with spaces in between each letter
    print(letter, end=' ')
print()

Change the correctLetters variable and play with the program until you figure out how it works.
There is a post in edmodo.com for you to submit the file and to explain how the program works.

Homework:
Write YI_WheelOfFortune.py using what you learned from Hangman.py

1. Have the variable secretWord changed to secretPhrase and have a value assigned to it.
2. Prompt the user for a letter and display it in the right positions if it is in the secretPhrase. Otherwise, send a message to the player “incorrect” and keep track of how many times the player guesses the wrong letters.
3. Terminate the game after 5 tries. Display “game over” if it fails. Otherwise, displays “You are a winner!!” and add message with the prize(s)

Classwork:

Two ways to create a dictionary in python:
1.

grocery1 = {'lettuce': 1.99, 'tomato': 0.49, 'onion': 0.35, 'olives': 0.99}

2.

grocery2 = {}
grocery2['lettuce'] = 1.99
grocery2['tomato'] = 0.49
grocery2['onion'] = 0.35
grocery2['olives'] = 0.99
grocery2
{'olives': 0.99, 'tomato': 0.49, 'onion': 0.35, 'lettuce': 1.99}

Two ways to insert a new key-value pair to the dictionary:
1.

grocery1['lemon'] = 0.78
grocery1
{'olives': 0.99, 'lemon': 0.78, 'tomato': 0.49, 'onion': 0.35, 'lettuce': 1.99}

2.

grocery1.update({'potato':1.10})
grocery1
{'lemon': 0.78, 'onion': 0.35, 'potato': 1.1, 'olives': 0.99, 'tomato': 0.49, 'lettuce': 1.99}

Two ways to create a list of the keys of the dictionary:
1.

keys = grocery1.keys()
keys
dict_keys(['lemon', 'onion', 'potato', 'olives', 'tomato', 'lettuce'])
for key in keys:
print(grocery1[key], end = '-')
0.78-0.35-1.1-0.99-0.49-1.99-

print(keys)
dict_keys(['onion', 'tomato', 'olives', 'lettuce'])
for key in keys:
print(key, end = ' ')
onion tomato olives lettuce

2.

keys_list = list(grocery1.keys())
keys_list
['lemon', 'onion', 'potato', 'olives', 'tomato', 'lettuce']
 

Two ways to create a list of values:
1.

values_list = []
for key in keys:
    values_list += [grocery1[key]]

values_list
[0.78, 0.35, 1.1, 0.99, 0.49, 1.99]
 

2.

val_list = grocery1.values()
val_list
dict_values([0.78, 0.35, 1.1, 0.99, 0.49, 1.99])
 

More to know:

x = 'lemon' in grocery
x
True

y = 'carrot' in grocery
y
False

How to delete a key-value entry pair from a dictionary:

grocery1 = {'lettuce': 1.99, 'tomato': 0.49, 'onion': 0.35, 'olives': 0.99}
del grocery1['lettuce']
grocery1
{'onion': 0.35, 'tomato': 0.49, 'olives': 0.99}

In edmodo.com
Homework:
Answer the following questions in edmodo.com

1. Do lists allow duplicate elements? what about dictionaries?

adict = {'a':1,'b':2,'a':4}
adict
{'a': 4, 'b': 2}

2. What are two ways to insert key–> value pairs into a dictionary.
3. Can different ‘types’ of keys be used in the same dictionary?
4. What happens when you try entering a value for a key that is already in the dictionary?
5. Create a scenario in which you would use a dictionary (without using the grocery example from these slides), and explain why you’d use a dictionary rather than a list.

Gota, you were right. Here is another way to add a key-value pair to a dictionary from stackoverflow.com

x = {1:2}
print x
{1: 2}

x.update({3:4})
print x
{1: 2, 3: 4}

Dictionaries in python

Interesting code found in some python Scrabble programs:

word = input("Enter a four letter word ")
word = word.upper()
letterNum = {'A':1,'E':1,'D':2,'R':2,'B':3,'M':3,'V':4,'Y':4,'J':8,'X':8}

What does the following line print?

print(letterNum['A'])

How was it used in the scrabble program?
One possible answer:

value = 0
for i in word:
    value += letterNum[i]

print(value)

Another possible answer:

letterValue = [0,0,0,0]
for i in range(4):
    letterValue[i] = letterNum[word[i]]

print(letterValue)

Classwork:
Work in python’s shell and copy and paste your work on edmodo.com’s post: Dictionary – Clwk 1/8 – Basic Concepts

Create a dictionary: ‘hello’ is the key and ‘hola’ is the value

spanishDictionary = {'hello':'hola','goodbye':'adios','one':'uno','two':'dos'}

Access a value with the key

word = input("what word would like to translate to spanish? ")
palabra = spanishDictionary[word]

Add a new key and value:

spanishDictionary.update({'blue':'azul'})
print(len(spanishDictionary))

Delete a key and the value:

del(spanishDictionary['blue'])

Replace the value of a key:

spanishDictionary['goodbye'] = 'chau'

Remove all items:

spanishDictionary.clear()

You can have a different type of value:

numbers = {'one':1,'two':2,'three':3,'four':4,'five':5}


print( numbers['two'] * numbers['three'])

You can have a different type of key and a different type of value:

numbers = {90:0,91:1,92:2,93:3}

print(numbers[92] * numbers[93])

Homework:
Add ten more words to the dictionary. Write a sentence in English and then translate it to Spanish or the language you chose. Add this new code to the original post.

Classwork: having fun with lists.

DIY Mad libs: Write your own mad lib program, YI_MadLibs.py using lists. You might want to have a theme.
Recipe:
1. Create 9 lists for adjectives, adverbs, nouns or plural nouns, verbs, exclamations, numbers, colors, and names. You can prompt the user for name to fill your list of names but all the other lists should already contained the items.

1. Generate 9 random digits one for each of the lists. The range will depend on the number of items each list has.
2. Create a sentence with the choice of each list. Make sure you put them in the right order!
3. Prompt the user whether he or she wants to play again.

NOTE:
Adjectives: describes something (green, squishy, cute)
Adverbs: describes an action (quickly, carefully, silently)
Nouns: person, place or thing (car, house, child)
Plural noun: people, places or things (cars, houses, children)
Verbs: an action (run, jump, swim)
Exclamations: wow!, oh!, yuck!

Something to keep in mind:
Find the words for your lists in such a way that fit “nicely” into your theme sentence.

You can play with this site to get an idea:

Dictionaries

Assignment:
Write a python program, YI_MySpanishDictionary.py using functions and dictionaries.

Note: You can use a different language. Name your program according to the language you are using.
• Hardcode a dictionary’s english word (key) and its spanish translation (value) for several english words (entries in the dictionary)
• Display a menu for the user to choose:
  1. Translate an english word
  2. Display all english words in the dictionary
  3. Add new english/spanish entries
  4. Delete english/spanish entries.

• Include an introduction
• Exit the program properly
• Do not forget to keep your code well documented
• Pasting your code on the post is a requirement
• Attaching your file is also a requirement

Graphics and Animations – Chapter 17

Homework:
Complete assignments

Classwork:
1. Write a python/pygame program, Olympic_Rings_YI.py. Draw the Olympic rings like the ones below.
Try to match up the colors and the relationship between the rings.

Link for antialiased circles.
This link has more drawing options.

2. Write a pygame program, Cars_n_trucks_YI.py to draw a random number of different cars and/or trucks of different colors. Look at some examples bellow.
Draw composite basic shapes

Note 1: make them (at least 2 kinds of vehicles) colorful and filled in.
Note 2: create functions: drawCar and drawTruck. Both functions should take two parameters: the scaling factor (suggested factor should be less than 1) and translation constant so it can be placed in different locations. For translation only, the scaling factor should be 1 and for scaling only the translation constant should be zero.
Note 3: the cars and trucks should be placed on the surface in random locations.
Note 4: Keep on reading chapter 17

Geometry review:
Dialation:

Translation:

Classwork:
Discussions on concepts you should know:

• pygame is so advanced that even the pygame module has its own modules
• pygame.locals module contains many constant variables QUIT, K_ESCAPE and many more.
• pygame.init() must always be included in your pygame programs
• pygame.display.set_mode((500, 400), 0, 32) creates a pop up window of width 500 pixels and height 400 pixels. 0 is used for more options and color 32 for depth. If you want to know more about this syntax, here is the link
• Surface object represents pop up windows.
• Differences between values and reference values: a list variable name is actually a reference, the contents of the list are the values.
• RGB referes to Red, Green and Blue
• This method: basicFont.render(‘Hello world!’, True, WHITE, BLUE) creates a Surface object with the text drawn on it
• Anti-aliasing can make your text and lines look blurry but smoother



• A pygame rectangle is an object: Rect((left, top), (width, height)).
  pygame.Rect(left, top, width, height)

Documentation

• pygame.Rect objects have attributes, variables that are associated with an object



• pygame.Rect objects have behaviors, methods that are associated with an object



• But you can draw a rectangle with this syntax:pygame.draw.rect(windowSurface, color,( x , y , width, heigth))
  where x is the x coordinate and y is the y-coordinate of the upper left corner of the rectangle.

• If you are including text in your pygmae window,
  text = basicFont.render(‘Hello world!’, True, WHITE, BLUE)
  textRect = text.get_rect()
  The next step then is to render the text by using the blit method:
  windowSurface.blit(text, textRect)
• Important: before blit-ting and before drawing: windowSurface.fill(WHITE)
• In Pygame, nothing is drawn to the screen until the pygame.display.update() function is called.
• Finally, no pygame should miss the next lines:
  while True:
  ….for event in pygame.event.get():
  ……..if event.type == QUIT:
  …………pygame.quit()
  …………sys.exit()
• The End

Homework:
Read chapter 17 topics we covered in class.

Next Chapter

Classwork: Modify pygameInput program so the the food falls down as if it were raining, YI_TheGoblerInput.py.

Homework: Read Source Code of the Keyboard Input Program from chapter 18 in the link.

Classwork:
Continue working on the program, WallBouncing_YI.py.

Home work: Keep on reading chapter 17.

Visit edmodo.com to answer the following questions from your reading material:
1. If a block is moving DOWNLEFT, how is the x coordinate behaving? how is the y coordinate behaving?
2. If a block is moving DOWNRIGHT, how is the x coordinate behaving? how is the y coordinate behaving?
3. If a block is moving UPLEFT, how is the x coordinate behaving? how is the y coordinate behaving?
4. If a block is moving UPRIGHT, how is the x coordinate behaving? how is the y coordinate behaving?
5. If a block is moving UPRIGHT, when would it bounce off the top of the window?
6. If a block is moving UPRIGHT, when would it bounce off the right side of the window?
7. If a block is moving DOWNRIGHT, when would it bounce off the bottom of the window?
8. If a block is moving UPLEFT, when would it bounce off the left side of the window?
9. Why did the author pick numbers 1, 3, 7, and 9 for the constants DOWNLEFT, DOWNRIGHT, UPLEFT AND UPRIGHT?

Think about your next program. It will be related to the animation.py but with a simple maze.

Classwork:
Run spritesAndSound.py

On edmodo.com:
1. What is the syntax to load an image?
2. What type of files can be images for pygame?
3. What is the syntax that defines the size of the image?
4. How do you create a pygame.mixer.Sound object?
5. What is the syntax to load the background music?
6. Describe the 3 argumenst in pygame.mixer.music.play(-1, 0.0).
Homework: Read chapter 19 – Sound and Images

Chapter 19 – Sound and Images link

Classwork:
Run spritesAndSound.py

Visit edmodo.com to answer 8 questions from chapter 19

Write a python/pygame program, mySpritesAndSound_YI.py similar to spritesAndSound.py. However, in this program there are no cherries and no player but when you click on the black surface an image shows up. Have 10 different images so when you click with the mouse one of those random images is selected for display. The image should disappear when you release the mouse button. Find two different sounds, one for clicking and one for the release of the mouse button. Make sure you use at least one list.

Note: there are libraries of sound files online. Look for the right one for your application.

Homework: Keep on reading chapter 19 – Sound and Images

Chapter 19 – Sound and Images link

Classwork:

Caesar Cipher
Create a new file in Idle with the following program: cipher.py

Cryptography

The science of writing secret codes is called cryptography.

German Lorenz cipher machine, used in World War II to encrypt very-high-level general staff messages

In cryptography, we call the message that we want to be secret the plaintext. The plaintext could look like this:

Hello there! The keys to the house are hidden under the flower pot.

How would encrypt it so it would become a secret message?

You can use Idle to answer some of the questions.

1. What is the ASCII table? What is the range of numbers that is used in the table?
2. What is the first number where the alphabet starts? Is it lower case or upper case?
3. How do you get the ASCII value of any letter or number (alphanumeric) in python?
4. How do you get the alphanumeric value of an integer in the range of the ASCII table?
5. Can you print all of the ASCII values?
6. Explain what a cipher is?
7. Run the cipher program and enter this sentence: “Doubts may not be pleasant, but certainty is absurd.” What is the encrypted sentence?
8. What does this ‘Hello’.isalpha() do in python shell?
9. What is the syntax to check if it is numeric?
10. What does this ‘HELLO’.isupper() do in python shell?
11. Explain what this code snippet does and what the purpose is in cipher.py:

if num > ord('Z'):
   num -= 26
elif num < ord('a'):
   num += 26

12. Explain the function getKey().
13. Explain the function getTranslatedMessage(mode, message, key).

Homework
Explain Brute Force