04 Prove Assignment: Writing Functions

Purpose

Prove that you can write functions with parameters and call those functions multiple times with arguments.

Problem Statement

In English, a preposition is a word used to express spatial or temporal relations, such as “in”, “over”, and “before”. A prepositional phrase is group of words that begins with a preposition and includes a noun. For example:

above the water
in the kitchen
after the meeting

Assignment

Write the second half of a Python program that generates simple English sentences that you began in the previous lesson’s prove milestone. As part of the previous lesson’s prove milestone, you wrote a program that generates English sentences with three parts: a determiner, a noun, and a verb. During this prove assignment, you will add functions so that your program generates sentences with four parts:

1. a determiner
2. a noun
3. a verb
4. a prepositional phrase

For example:

One girl talked for the car.
A bird drinks off one child.
The child will run on the car.
Some dogs drank above many rabbits.
Some children laugh at many dogs.
Some rabbits will talk about some cats.

To complete this prove assignment, your program must include at least these seven functions:

1. main
2. make_sentence
3. get_determiner
4. get_noun
5. get_verb
6. get_preposition
7. get_prepositional_phrase

You may add other functions if you find them helpful. The get_preposition function must randomly choose a preposition from a list and return the randomly chosen preposition. The get_prepositional_phrase function must make a prepositional phrase by calling the get_preposition, get_determiner, and get_noun functions.

Helpful Documentation

• The preparation content for lesson 2 explains how to call functions.
• The preparation content for lesson 3 explains how to write functions.
• The preparation content for this lesson explains variable scope and good function design.

Steps

Do the following:

1. Use the get_determiner function from the previous lesson’s prove milestone as an example to help you write the get_preposition function. The get_preposition function must have the following header and fulfill the requirements of the following documentation string.

   def get_preposition():
       """Return a randomly chosen preposition
       from this list of prepositions:
           "about", "above", "across", "after", "along",
           "around", "at", "before", "behind", "below",
           "beyond", "by", "despite", "except", "for",
           "from", "in", "into", "near", "of",
           "off", "on", "onto", "out", "over",
           "past", "to", "under", "with", "without"
   
       Return: a randomly chosen preposition.
       """
   

2. Write the get_prepositional_phrase function to have the following header and fulfill the requirements of the following documentation string.

   def get_prepositional_phrase(quantity):
       """Build and return a prepositional phrase composed
       of three words: a preposition, a determiner, and a
       noun by calling the get_preposition, get_determiner,
       and get_noun functions.
   
       Parameter
           quantity: an integer that determines if the
               determiner and noun in the prepositional
               phrase returned from this function should
               be single or pluaral.
       Return: a prepositional phrase.
       """
   

3. Add code to the make_sentence function and write any other functions that you think are necessary for your program to generate and print six sentences, each with a determiner, a noun, a verb, and a prepositional phrase. The six sentences must have the following characteristics:

   	Quantity	Verb Tense
   a.	single	past
   b.	single	present
   c.	single	future
   d.	plural	past
   e.	plural	present
   f.	plural	future

Call Graph

The following call graph shows the user-defined functions and function calls and returns as you should write them in your sentences.py program. From this call graph we see the following function calls:

1. The computer starts executing the sentences.py program by calling the main function.
2. While executing the main function, the computer calls the make_sentence function.
3. While executing the make_sentence function, the computer calls the get_determiner, get_noun, get_verb, and get_prepositional_phrase functions.
4. While executing the get_prepositional_phrase function, the computer calls the get_preposition, get_determiner, and get_noun functions.
5. While executing each of the get_determiner, get_noun, get_verb, and get_preposition functions, the computer calls the random.choice function.
6. Then, the computer executes the str.capitalize method.
7. Finally, the computer executes the print function.

Testing Procedure

Verify that your test program works correctly by following each step in this procedure:

1. Run your sentences.py program and ensure that your program’s output is similar to the sample run output shown here. Because your program randomly chooses the determiners, nouns, verbs, and prepositions, your program will generate different sentences than the ones shown here.

   > python sentences.py
   One girl talked for the car.
   Some dogs drank above many rabbits.
   One bird drinks off one child.
   Some children laugh at many dogs.
   The child will run on the car.
   Some rabbits will talk about some cats.

Exceeding the Requirements

If your program fulfills the requirements for this assignment as described in the previous prove milestone and the Assignment section above, your program will earn 93% of the possible points. In order to earn the remaining 7% of points, you will need to add one or more features to your program so that it exceeds the requirements. Here are a few suggestions for additional features that you could add to your program if you wish.

• Within your make_sentence function add another call to get_prepositional_phrase so that each sentence includes two prepositional phrases like this:

  One girl across one cat talked for the car.
  A bird near the rabbit drinks off one child.
  The child under the cat will run on the car.
  Some dogs without a cat drank above many rabbits.
  Some children from a bird laugh at many dogs.
  Some rabbits behind one man will talk about some cats.

• Write a function named get_adjective and call it in your make_sentence function to add an adjective to the sentences produced by your program. Does it make sense to call get_adjective in your get_prepositional_phrase function?
• Write a function named get_adverb and call it in your make_sentence function to add an adverb to the sentences produced by your program.

Ponder

What changes would you have to make to your program so that it could produce sentences that fit the following form?

{Determiner} {adjective} {noun} {prepositional_phrase} {adverb} {verb} {determiner} {adjective} {noun} {prepositional_phrase}.

Such as these sentences:

The red birds in the air quickly ate some fast fish in the water.
The busy bird with a car sweetly drank many smart rabbits by one boy.
One dinky boy near the dog calmly grew some tall children across a cat.

How hard would it be to modify your program to pass the Turing test?

Submission

To submit your program, return to I‑Learn and do these two things:

1. Upload your sentences.py file for feedback.
2. Add a submission comment that specifies the grading category that best describes your program along with a one or two sentence justification for your choice. The grading criteria are:

   1. Some attempt made
   2. Developing but significantly deficient
   3. Slightly deficient
   4. Meets requirements
   5. Exceeds requirements