Introduction to Python

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Projects, Session 10



EXTRA CREDIT / SUPPLEMENTARY ONLY THIS WEEK
 
10.1 (Extra credit / Supplementary): Create a class, Square, each of whose instances (i.e., each Square object) have an attribute which is an integer. Each Square object has the following methods:

a. __init__(): set the integer attribute to 2. b. def squareme(self): square the integer attribute and store the new squared value in the attribute, replacing the old value (i.e. the first time you call it, it will replace 2 with 4. c. def getme(self): return the integer attribute. Sample usage (your code must be able to behave as shown below, including being able to create multiple arguments with their own data -- PLEASE MAKE SURE YOUR OBJECTS HOLD THEIR OWN DATA -- MAKE SURE THEY CAN BEHAVE EXACTLY AS SHOWN BELOW, ESPECIALLY THE FINAL LINES OF THE EXAMPLE USAGE). Also, make sure you can create any number of objects, not just three!

Test program, with output samples shown in comments to right 
# all output must match!

n1 = Square()
n2 = Square()
n3 = Square()

n1.squareme()
val1 = n1.getme()
print val1               # 4

n2.squareme()
n2.squareme()
val2 = n2.getme()
print val2               # 16
print n1.getme()         # 4

n3.squareme()
n3.squareme()
n3.squareme()
n3.squareme()
n3.squareme()
val3 = n3.getme()
print val3               # 4294967296

print n1.getme()         # 4
print n2.getme()         # 16
print n3.getme()         # 4294967296
Expected Output: 
4
16
4
4294967296
4
16
4294967296


HOMEWORK CHECKLIST: all points are required

    testing: you have run the program with the sample inputs as shown and are seeing the output exactly as shown (contact me if your output is different and you're unable to adjust to match)
    the program works exactly as shown in the sample output
    there are no extraneous comments or "testing" code lines
    program follows all recommendations in the "Code Quality" handout

 
10.2 (Extra credit / supplementary): List of a Maximum Size. Create a class, MaxSizeList, that constructs instances that have a list as an attribute (set as an empty list in __init__). The constructor takes an integer as an argument, which becomes the maximum size of the list (stored as a second attribute).

Add a method, push(), which appends a value to the list. However, if the list has already reached its maximum size (as set in the constructor), remove the first element from the list before appending the new element to the list. (You can use the list method pop() with an argument of 0 to remove the first element of the list, or you can use a slice (alist = alist[1:]).)

Sample code to use the class and expected output: 
a = MaxSizeList(3)
b = MaxSizeList(1)

a.push("hey")
a.push("ho")
a.push("let's")
a.push("go")

b.push("hey")
b.push("ho")
b.push("let's")
b.push("go")

print(a.get_list())     # ['ho', "let's", 'go']
print(b.get_list())     # ['go']


HOMEWORK CHECKLIST: all points are required

    testing: you have run the program with the sample inputs as shown and are seeing the output exactly as shown (contact me if your output is different and you're unable to adjust to match)
    the program works exactly as shown in the sample output
    there are no extraneous comments or "testing" code lines
    program follows all recommendations in the "Code Quality" handout

 
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