IT 117: Intermediate Scripting

IT 117: Intermediate Scripting
Homework 10

Due
What You Need to Do
Setup On Your Machine
Specification
Test Code
Output
Suggestions
Testing on Your Machine
Copy the Script to Unix
Testing the Script on Unix (Optional)

Due

Sunday, April 20th at 11:59 PM

What You Need to Do

Create the script hw10.py
Make sure it obeys the rules in Rules for Homework Scripts
Make sure the script has a hashbang line and is executable
Move it to an an hw10 directory on pe15.cs.umb.edu

Setup On Your Machine

Open a text editor.
I would suggest the text editor built into the program IDLE.
Save the file as hw10.py

Specification

Define the class Pet with the following hidden attributes
- name
- type
- age
The constructor will set all attributes
But it must ckeck that the value for type is either "dog" or "cat"
It must also check that the value for age can be convertered into an integer
If either of these values is no correct, an error message must be printed
The class must have 6 methods in addition to the constructor
- get_name(self)
- get_type(self)
- get_age(self)
- __gt__(self, other)
- __str__(self)
- older(self, other)
__gt__ should return true if the objects age attribute is greater than the age calue of the other object
The string returned by __str__ should return the value of all attributes
older should compare the age of the object to that of another Pet object
It should then print a message like that you see below in Output

Test Code

Your script must contain the following statements

They should appear at the bottom of your script

if __name__ == "__main__":    
    p1 = Pet("Henry", "dog", 7)
    print(p1)     
    p1 = Pet("Henry", "dawg", 7)
    p1 = Pet("Henry", "dog", "seven")
    
    print()
    p1 = Pet("Henry", "dog", 7)
    print(p1.get_name())
    print(p1.get_type())
    print(p1.get_age())
    
    print()
    p2 = Pet("Felix", "cat", 2)
    print("Henry age > Felix age:", p1 > p2)
    p2.older(p1)
    p1.older(p2)
    
    print()
    p3 = Pet("Angus", "dog", 7)
    p3.older(p1)
    p1.older(p3)

Output

The output should look something like this

Henry, dog, 7
dawg is not a valid pet type
seven cannot be converted into an integer

Henry
dog
7

Henry age > Felix age: True
Felix is younger than Henry
Henry is older than Felix

Henry and Angus are the same age
Angus and Henry are the same age

Suggestions

Write this script in stages
Test your script at each step
Print the steps below
And check them off as you finish each one

Add a header for the class Pet to the script.
Create the method header for the constructor __init__ with parameters self, name, type, and age.
For the body of this function, use a pass statement.
Run the script and fix any errors you find.
Copy the test code to the bottom of the script.
Comment out all the statements after
```
p1 = Pet("Henry", "dog", 7)
```
Add assignment statements for each of the attributes.
Remember the attributes must be hidden.
Run the script and fix any errors you find.
Create method __str__ that returns a string containing the value of all attributes with a comma between them.
Remember to convert age to a string.
Remove the # from the next line in the test code.
Run the script and fix any errors you find.
Remove the assignment statement for type in the constructor.
Replace it with an if statement that checks if the vaule of type is contained in the list ["dog", "cat"].
If the value passes this test, set type to this value.
If not, print an error message.
Remove the # from the next line in the test code.
Run the script and fix any errors you find.
Remove the assignment statement for age in the constructor.
Replace it with an try/except statement.
Inside the try block covert the age value to an integer and set the age attribute to this value.
in the else clause print an error message.
Remove the # from the next line in the test code.
Run the script and fix any errors you find.
Create the accesor method get_name that returns the value of title.
Remove the # from the next three lines in the test code.
Run the script and fix any errors you find.
Create the accesor method get_type that returns the value of type.
Remove the # from the next line in the test code.
Run the script and fix any errors you find.
Create the accesor method get_age that returns the value of age.
Remove the # from the next line in the test code.
Run the script and fix any errors you find.
Create the method __gt__ which has two parameters, self and other.
This method will return the vaule of the boolean expressios asking if the age of self is greater than the age of other.
Remove the # from the next three lines in the test code.
Run the script and fix any errors you find.
Write an if statement that checks if the age of self is greater than the age of other.
If it is, print print a message that uses the names of the two pets to say that self is older than other.
Add an elif clause that checks if the age of other is greater than the age of self.
If it is, print a message that uses the names of the two pets to say that other is older than self.
Run the script and fix any errors you find.
Add an else clause that prints a message using the names of the two pets saying that both are the same age.
Run the script and fix any errors you find.

Testing on Your Machine

Open IDLE
Use the Open command in IDLE to open hw10.py
Under the Run menu, select Run Module

Your output should look something like this

Henry, dog, 7
dawg is not a valid pet type
seven cannot be converted into an integer

Henry
dog
7

Henry age > Felix age: True
Felix is younger than Henry
Henry is older than Felix

Henry and Angus are the same age
Angus and Henry are the same age

Copy the Script to Unix

Open FileZilla and connect to pe15.cs.umb.edu
Go to your it117 directory
Go to your hw directory
Right-click in the whitespace inside the hw directory
Enter hw10 in the dialog box
Click and drag your script from the bottom left panel to the bottom right panel
Right-click on the file and select "Permissions" from the menu
Enter 755 in the box provided
This will make the script executable

Testing the Script on Unix (Optional)

Connect to pe15.cs.umb.edu using an ssh client like putty.exe (Windows) or ssh (Mac)
Go to the directory for this exercise
```
cd  it117/hw/hw10
```
Run this script
```
python3 hw10.py
```

You should see something like this

Henry, dog, 7
dawg is not a valid pet type
seven cannot be converted into an integer

Henry
dog
7

Henry age > Felix age: True
Felix is younger than Henry
Henry is older than Felix

Henry and Angus are the same age
Angus and Henry are the same age