IS 210 Assignment 04

Warmup Tasks

College:	CUNY School of Professional Studies
Course-Name:	Software Application Programming I
Course-Code:	IS 210

Overview

In this assignment, we'll focus on the construction of basic functions. The functions we create will be intentionally simple to make it easier to isolate the task at hand.

Instructions

The following tasks will either have you interacting with existing files in the assignment repository or creating new ones on the fly. Don't forget to add your interpreter directive, utf-8 encoding, and a short docstring with any new files that you create!

Important

In these exercises, you may, on occasion, come across a task that requres you to research or use a function or method not directly covered by the course text. Since Python is such a large language it would be impossible for the author to have included descriptions of each and every available function which would largely duplicate the offical Python documentation.

A vital skill to successful programming is being comfortable searching for and using official language documentation sources like the Python String Documentation page. Throughout our coursework we will be practicing both the use of the language in practice and the search skills necessary to become functional programmers.

Warmup Tasks

Task 01

Functions have their own documentation standards which are covered in the Google Python Style Guide. Document the function found here appropriately.

Warning

Neither Lint nor Unit tests will test the quality of your documentation or whether or not it's formatted correctly. You must document each function correctly in order to receive credit.

Hint

Indentation and spacing both matter so pay attention to how you indent the headers and the sections.

Hint

Remember that optional parameters should be indicated as-such in their declaration!

Specifications

1. Document the function in task_01.py according to the Google Python Style Guide.

Hint

You can use the help() function to test your docstring as below.

Examples

>>> import task_01
>>> help(task_01.know_what_i_mean)

Task 02

Calling a function is already something we've done a few times but let's practice it again just to make sure we've connected the dots.

Specifications

1. Open hamlet.py to get a sense of what this function does.
2. Open task_02.py and call the hamlet.crazy_math() math function assigning it the following parameters in order:
   1. 4
   2. 100000
   3. 8
   4. 98
3. Assign the returned result to a new global variable named POSITIONAL

Examples

>>> import task_02
>>> print task_02.POSITIONAL
0.00374391674995

Task 03

Positional parameters may suffice in many cases but most programmers prefer to use keyword arguments. Here you'll call a function with keyword arguments instead of positional parameters.

Specifications

1. Open hamlet.py to get a sense of what this function does.
2. Open task_03.py and call the hamlet.crazy_math() math function assigning it the following parameters by keyword reference:
   1. bananas: 48
   2. monkeys: 84
   3. hours: 200000
3. Assign the returned result to a new global variable named KEYWORD

Examples

>>> import task_03
>>> print task_03.KEYWORD
0.00879168510437

Task 04

In this task, you'll be defining a function with three parameters.

Specifications

1. Create a new file names task_04.py

2. Define a new function named too_many_kittens that takes three arguments, in order:

   1. kittens, the number of kittens
   2. litterboxes, the (integer) number of available litterboxes
   3. catfood, a boolean representing whether or not any catfood exists

3. In the function return the value of the following comparison statement:

   not (litterboxes >= kittens and catfood)

   This statement ensures we have at least one litterbox for each kitten and that we have some catfood. It then uses inversion via not to answer whether or not we have too many kittens.

Note

Note the spacing of the not operator. There should always be spacing around all logical operators like and, not or or. Without it, not would look like a function, eg not().

Note

A fun fact of the polymorphic properties of python is the fact that truthiness would allow catfood to either be a boolean (eg, True) or some number like 0 or even None and this would continue to operate in a reasonably sane manner.

Examples

>>> too_many_kittens(12, 12, False)
True

>>> too_many_kittens(13, 12, True)
True

>>> too_many_kittens(12, 13, True)
False

Task 05

Here we'll set a default value in our function definition.

Specifications

1. Create a file named task_05.py

2. Create a new function named defaults with two parameters:

   1. my_optional which has a default value of True
   2. my_required which is a required param and has no default value

3. Return the following logical comparison:

   my_optional is my_required

Examples

>>> defaults(True)
True

>>> defaults(True, False)
False

>>> defaults(False, False)
True

Executing Tests

Code must be functional and pass tests before it will be eligible for credit.

Linting

Lint tests check your code for syntactic or stylistic errors To execute lint tests against a specific file, simply open a terminal in the same directory as your code repository and type:

$ pylint filename.py

Where filename.py is the name of the file you wish to lint test.

Unit Tests

Unit tests check that your code performs the tested objectives. Unit tests may be executed individually by opening a terminal in the same directory as your code repository and typing:

$ nosetests tests/name_of_test.py

Where name_of_test.py is the name of the testfile found in the tests directory of your source code.

Running All Tests

All tests may be run simultaneously by executing the runtests.sh script from the root of your assignment repository. To execute all tests, open a terminal in the same directory as your code repository and type:

$ bash runtests.sh

Submission

Code should be submitted to GitHub by means of opening a pull request.

As-of Lesson 02, each student will have a branch named after his or her GitHub username. Pull requests should be made against the branch that matches your GitHub username. Pull requests made against other branches will be closed. This work flow mimics the steps you took to open a pull request against the pull branch in Week Two.

For a refresher on how to open a pull request, please see homework instructions in Lesson 01. It is recommended that you run PyLint locally after each file is edited in order to reduce the number of errors found in testing.

In order to receive full credit you must complete the assignment as-instructed and without any violations (reported in the build status). There will be automated tests for this assignment to provide early feedback on program code.

When you have completed this assignment, please post the link to your pull request in the body of the assignment on Blackboard in order to receive credit.