CSC111 Homework 10 2014

--D. Thiebaut (talk) 10:30, 8 April 2014 (EDT)

---

Page under construction!

Problem #1

The program below is missing its class! And it is also missing its documentation! It used to contain a class defined, with methods and member variables, and a fully developped documentation, but unfortunately all of them got erased.

We do have the output of a run of the program, though, when it still had its class definition. Both the incomplete code and the output are shown below.

def getNewCat():
    print( "\nPlease enter the information for the new cat:")
    name = input(       "Cat name?         " )
    age  = int( input(  "Age, in years?    " ) )
    vac  = input(       "Vaccinated (Y/N)? " ).strip().lower()
    vac  = vac in ['y', 'yes']
    neut = input(       "Neutered (Y/N)?   " ).strip().lower()
    neut = neut in ['y', 'yes' ]
    breed= input(       "Breed?            " ).strip()
    
    return Cat( name, age, vac, neut, breed )

def main():
    text="""Minou, 3, Yes, Yes, stray
            Max, 1, Yes, No, Burmese
            Gizmo, 2, No, No, Bengal
            Garfield, 4, Yes, Yes, Orange Tabby"""

    for line in text.split( "\n" ):
        words = line.strip().split( "," )
        if len( words ) != 5:
            continue
        name, age, vaccinated, neutered, breed = words
        age = int( age.strip() )
        if vaccinated.strip().lower() == "yes":
            vaccinated = True
        else:
            vaccinated = False

        neutered = neutered.strip().lower() == "yes":
        
        cat = Cat( name.strip(), age, vaccinated, neutered, breed.strip() )
        try:
            cats.append( cat )
        except NameError:
            cats = []
            cats.append( cat )

    display( cats, "List of cats:" )

    cats.append( getNewCat() )

    display( cats, "List of cats with new addition:" )

    vaccinatedNeuteredCats = []
    for cat in cats:
        if cat.isVaccinated() and cat.isNeutered():
            vaccinatedNeuteredCats.append( cat )

    display( vaccinatedNeuteredCats, "Vaccinated and neutered cats" )
    
    
main()

Output

List of cats:
=============
Cat: Minou, age: 3, vaccinated, neutered (stray)
Cat: Max, age: 1, vaccinated, not neutered (Burmese)
Cat: Gizmo, age: 2, not vaccinated, not neutered (Bengal)
Cat: Garfield, age: 4, vaccinated, neutered (Orange Tabby)

Please enter the information for the new cat:
Cat name?         Ralph
Age, in years?    4
Vaccinated (Y/N)? y
Neutered (Y/N)?   y
Breed?            Angora


List of cats with new addition:
===============================
Cat: Minou, age: 3, vaccinated, neutered (stray)
Cat: Max, age: 1, vaccinated, not neutered (Burmese)
Cat: Gizmo, age: 2, not vaccinated, not neutered (Bengal)
Cat: Garfield, age: 4, vaccinated, neutered (Orange Tabby)
Cat: Ralph, age: 4, vaccinated, neutered (Angora)


Vaccinated and neutered cats
============================
Cat: Minou, age: 3, vaccinated, neutered (stray)
Cat: Garfield, age: 4, vaccinated, neutered (Orange Tabby)
Cat: Ralph, age: 4, vaccinated, neutered (Angora)

Question

Recreate the original program with its Cat class. Make sure that it will generate the same output show above if fed the same cat information.

Document your code well, including the main and getNewCat functions. Document the class using the same approach as in this file: Planets.py.
Store your program in a file called hw10a.py and submit it here.

Problem #2

This problem was originally part of Lab #10.
Copy the code in this page and store it in a new Python file called Planets.py. Save it in your current working directory (where your other Python programs are).

Create a new program called hw10b.pyand add the code below to it.

from Planets import PlanetList

def playWithPlanets():
    planets = PlanetList()
    print( planets )


def main():
    playWithPlanets()

main()

• Run your program to see how it behaves.
• Study the class PlanetList, and figure out how each method works.

Your assignment

• Add code to your hw10b.py program so that it will
  1. display the name of the smallest planet
  2. display the name of the largest planet
  3. display the number of planets
  4. get the user to input a new planet that will be added to the list of planets (this page has good information on planets)
  5. display the new list of names of planets

NOTE: you cannot modify the code inside the class!

Store your program in a file called hw10b.py and submit it here.

Problem #3

Create a new program with the code below. Call it hw10c.py.

# 
class Person:
    # a class containing 4 private member variables:
    # - name of the person (string)
    # - age (integer)
    # - gpa (float)
    # - major (string, uppercase)
    # methods:
    # getName(): returns the name of the person (string)
    # getAge(): returns the age of the person (int)
    # setAge(x): sets the age of the person to x (int)

    # constructor: intializes a person with all fields
    def __init__(self, n, a ):
        self._name = n
        self._age  = a

    # returns a string with the name and age.
    def __str__( self ):
        return "%s, %d years old" % ( self._name, self._age )

    # returns the name
    def getName( self ):
        return self._name

    # set the age to a new value x
    def setAge( self, x ):
        self._age = x

    # returns the age of the person
    def getAge( self ):
        return self._age


class Dog:
    # a class containing 2 private member variables:
    # - name-tag of the dog (string)
    # - whether the dog is vaccinated or not (boolean)
    # methods:
    # isVaccinated(): returns True if the dog is vaccinated, False otherwise
    # getName(): returns the name-tag of the dog
    # setName(x): sets the name-tag of the dog
    # constructor
    def __init__( self, tag, vaccinated ):
        self._tag = tag
        self._vaccinated = vaccinated

    # default string representation for the dog
    def __str__( self ):
        if self._vaccinated==True:
            return "%s (vaccinated)" % self._tag
        return "%s (not vaccinated)" % self._tag

    # isVaccinated: returns True if the dog is vaccinated, False otherwise
    def isVaccinated( self ):
        return self._vaccinated

    # returns the name of the dog
    def getNameTag( self ):
        return self._tag

    # changes the name-tag 
    def setNameTag( self, tag ):
        self._tag = tag


class ListPeopleDog:
    # a class that maintains a list of pairs.  The first
    # element of a pair is a Person object, the second a Dog object
    # if the person doesn't have a dog, the second element of the pair is None
    # Methods supported:
    # isEmpty(): returns True if the list is empty, False othewise
    # append( p, d ): appends a pair( person, dog) to the list
    # getDogOf( name ): returns the dog object associated with the given person's name
    # getOwnerOf( tag ): returns the person object associated with the given dog tag
    # size( ): returns the number of pairs in the list
    # getPersonDogAt( i ): returns the person object and the dog object located 
    # at Index i in the list.

    # constructor
    def __init__( self ):
        self._L = []

    # returns a string formatted as several lines, each representing
    # a person and his/her dog.
    def __str__( self ):
        s = ""
        for person, dog in self._L:
            if dog==None:
                s = s + str( person )+ " [No dogs]\n"
            else:
                s = s + str( person )+ " ["+str( dog ) +"]\n"
        return s
    
    # returns True if the list is empty.  False otherwise.
    def isEmpty( self ):
        return len( self._L )==0

    # add a new pair to the list
    def append( self, person, dog ):
        self._L.append( (person, dog) )

    # returns the dog associated with the first person who's name is passed.
    def getDogOf( self, name ):
        name = name.strip().lower()
        for person, dog in self._L:
            if dog==None:
                continue
            if person.getName().lower() == name:
                return dog
        return None

    # returns the person object associated with the first dog in the list with the
    # tag passed as a parameter.
    def getOwnerOf( self, name ):
        name = name.strip().lower()
        for person, dog in self._L:
            if dog==None:
                continue
            if dog.getNameTag()==name:
                return person
        return None
 
    # returns the number of pairs in the list.
    def size( self ):
        return len( self._L )

    # returns the person and dog located at Index i in the list.
    def getPersonDogAt( self, i ):
        if i < len( self._L ):
            return self._L[i][0], self._L[i][1]
        return None, None
        
# ================================================
#                     main
# ================================================
def main():
    text = """Joe, 23, Fido, vaccinated
              Debra, 30, Rex, not vaccinated
              Frida, 10, Ralph, vaccinated
              Maria, 21, Gizmo, vaccinated
              Frank, 31, ,
              Millie, 25, Maxi, no vaccinated"""
    
    # create a new ListPeopleDog object    
    L = ListPeopleDog()
    
    # parse the text and add it as people-dog pairs in the list
    for line in text.split( "\n" ):
        if len( line.split(',') ) != 4:
            continue
        name, age, tag, vacc = line.split(',')
        name = name.strip()
        age  = int( age.strip() )
        tag  = tag.strip()
        vacc = "not" not in vacc.lower()

        if len( tag )==0:
            L.append( Person(name, age), None  )
        else:
            L.append( Person(name, age), Dog( tag, vacc )  )

    # Display the list
    for i in range( L.size() ):
        p, d = L.getPersonDogAt( i )
        if d != None:
            print( p, "has a dog: ", d )


main()

Your Assignment

• Without modifying any of the classes, make your program output
  1. the list of people who have unvaccinated dogs
  2. the list of people without dogs
  3. the oldest person who has a dog

An example of the output of the solution program is shown below:

Joe, 23 years old has a dog:  Fido (vaccinated)
Debra, 30 years old has a dog:  Rex (not vaccinated)
Frida, 10 years old has a dog:  Ralph (vaccinated)
Maria, 21 years old has a dog:  Gizmo (vaccinated)
Millie, 25 years old has a dog:  Maxi (vaccinated)
Debra, 30 years old has a non vaccinated dog called Rex
Frank, 31 years old doesn't have a dog
The oldest person to own a dog is Debra, 30 years old and the dog is Rex (not vaccinated)

Store your program in a file called hw10c.py and submit it here.