CSC111 Lab 6 2014

--D. Thiebaut (talk) 15:00, 3 March 2014 (EST)

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Old MacDonald's Farm

Old MacDonald's farm is a song (almost) all American kids learn at one point in their life. I certainly never heard it when I grew up in France, but I think most of you will be familiar with it. If you don't know it, this YouTube video will get you acquainted with it. :-)

The goal of this problem is for you to add a section to the program below so that it prints parts of the lyrics of the famous song using a for-loop and functions.

Here's the beginning program which you have to modify:

# start with four animals in the farm
farm = [ "horse", "pig", "dog", "cat" ]

# sing(): a function that simulates singing a refrain for the song
# using the animal name.     
def sing( word ):
     print( word )

# "sing" all the names of the animals
for animal in farm:
     sing( animal )

• Create the program in lab6.py and run it.

Challenge 1

• Modify the function so that the output looks like the lyrics of the song:

    And on his farm he had a horse, E-I-E-I-O
    
    And on his farm he had a pig, E-I-E-I-O
    
    And on his farm he had a dog, E-I-E-I-O
    
    And on his farm he had a cat, E-I-E-I-O

• Make sure there's a blank line between each line with an animal name.

Challenge 2

• Modify the function some more so that the output looks like the lyrics of the song:

    Old MacDonald had a farm, E-I-E-I-O
    And on his farm he had a horse, E-I-E-I-O
    Here a horse, there a horse, everywhere a horse!
    
    Old MacDonald had a farm, E-I-E-I-O
    And on his farm he had a pig, E-I-E-I-O
    Here a pig, there a pig, everywhere a pig!
    
    Old MacDonald had a farm, E-I-E-I-O
    And on his farm he had a dog, E-I-E-I-O
    Here a dog, there a dog, everywhere a dog!
    
    Old MacDonald had a farm, E-I-E-I-O
    And on his farm he had a cat, E-I-E-I-O
    Here a cat, there a cat, everywhere a cat!

Challenge 3

• Modify your program a third time, and introduce a new function that will receive 4 animals as parameters, and will call the function sing( ) for each one.

Here is an outline of what your final program should look like (you have to figure out what to replace the ellipses with!)

def sing( word ):
     print( ... )
     print( ...  word ... )
     print( ... )

def singSong( animal1, animal2, animal3, animal4 ):
     sing( animal1 )
     sing( animal2 )
     sing( animal3 )
     sing( animal4 )


singSong( "horse" ... )

Disney's Dwarves in Boxes

• We have seen before how to print the name of Disney's seven dwarves:

seven = [ "Sleepy", "Sneezy", "Bashful", "Happy", "Grumpy", "Dopey", "Doc" ]

for name in seven:
    print( name )

• We saw in class a function that puts a box around a string:

def box( string ):
    line = "+"  +  ("-"*len( string ) )  + "+" 
    print( line )
    print( "|" + string + "|" )
    print( line )
    print()

• Create a program that uses the code snipets above and prints the names of the 7 dwarves in boxes:

+------+
|Sleepy|
+------+

+------+
|Sneezy|
+------+

+-------+
|Bashful|
+-------+

+-----+
|Happy|
+-----+

+------+
|Grumpy|
+------+

+-----+
|Dopey|
+-----+

+---+
|Doc|
+---+

Minions, Theater Production, and Functions

• Review the games we played in class about directing a play with students who say sentences... This section asks you to write the code for more script.

Game 6

Here's a new game. Read it, figure out what the minions are supposed to do, and translate it into Python code.

• Student 1 ( sentence )
  • Get sentence
  • say the sentence in UPPERCASE

• Student 2 (sentence )
  • get sentence
  • say the sentence in lowercase

• Student 3 (sentence1, sentence2 )
  • get sentence1 and sentence2
  • ask Student 1 to say "shhhhhhh!"
  • ask Student 1 to say sentence1
  • ask Student 2 to say setnence2
  • ask Student 2 to say "thank you"

• Call Student 3 and pass "Welcome" and "to CSC111 Lab 6!"

Chessboard

Something Different

• Paste the code below in Idle. Figure out what it does before running it. Then run it.

 isGood = True
 for i in range( 5 ):
	print( isGood )
	isGood = not isGood

We have seen how to modify integer variables inside for-loops. We can also use boolean variable and "flip" them every loop to make them have opposite values one loop to the next. This may come in handy at some point :-)

Printing a Simple Small Chessboard

• Copy/paste the program below in Idle:

def printBlock( visible ):
    if visible==True:
        print( "#", end="" )
    else:
        print( ".", end="" )

def printLine( visibility ):
    printBlock( visibility )
    printBlock( not visibility )
    printBlock( visibility )
    printBlock( not visibility )
    print()

printLine( True )

• Run the program.
• Figure out how it generated the line #.#. Make sure you understand how this happened.

• Now change the last line of the program and replace True by False.
• Observe the new output. Figure out how the program reverses the output to .#.#

Challenge 4

Modify the program (including the functions) so that its output becomes:

#.#.#.#.#.#.#.#.
.#.#.#.#.#.#.#.#
#.#.#.#.#.#.#.#.
.#.#.#.#.#.#.#.#
#.#.#.#.#.#.#.#.
.#.#.#.#.#.#.#.#
#.#.#.#.#.#.#.#.
.#.#.#.#.#.#.#.#

which represents an 8x8 chessboard where the while cells are represented by dots and the black cells by hash-tags.

Challenge 5

Same as Challenge 4, but make sure your program uses a for-loop to print the 8 symbols on each line, and a for-loop to print the 8 lines.