Code Projects¶

modular design
minimal viable product
rapid prototyping
project organization
refactoring

Project Check-In¶

Do you have an idea of what you want to do for your project?

A) Absolutely no Idea
B) Some idea, but not sure
C) Sort of
D) Fairly good idea
E) I know exactly what I want to do

How much code do you have written for your project?

A) None
B) A little or some pseudocode
C) Some
D) A lot
E) Most (I’m mostly or completely done)

How confident do you feel about what you need to do to finish the project?

A) I have no idea what to do from here
B) I have some idea of how to finish the project
C) I have a reasonable idea of what to do from here
D) I have a very good idea of what to do
E) I completely know / am basically finished

Modular Design¶

Modular design, like modular programming, is the approach of designing and building things as independent modules.

Minimal Viable Product¶

A 'minimal viable product' is a product that contains the minimum amount of implemented features to use the code product - no more, no less.

Rapid Prototyping¶

Rapid prototyping is an approach for developing things in which you work on minimal prototypes and iterate on them quickly.

Some examples¶

Chatbot: start and end a chat
Data Analysis: read a dataset in, make a basic plot
Car Inventory: object with method that adds a car to the Inventory
Artificial Agents: simple bot moves around randomly

Project Organization¶

Organizing Code¶

Notebooks: good for interactive development
- For when seeing the inputs and outputs of code running needs to be seen start to finish
- file ends in .ipynb
Modules: for storing mature Python code, that you can import
- you don’t use the functions in there, just define them
- file ends in .py
Scripts: a Python file for executing a particular task
- this takes an input and does something start to finish
- file ends in .py

Project Workflow¶

Typical project workflow:

Develop code interactively in a Jupyter notebook/text editor
As functions & classes become mature, move them to Python files that you then import
- As you do so, go back through them to check for code style, add documentation, and write some code tests
At the end of a project, (maybe) write a standalone script that runs the project

Code Review¶

Code reviews is a process for systematically reviewing someone else's code.

This is what you’ll have the chance to do in coding lab this week!

Refactoring¶

Refactoring is the process of restructuring existing computer code, without changing its external behaviour.

Think of this as restructuring and final edits on your essay.

Nesting Functions - If you have a whole bunch of functions, if statements, and for/while loops together within a single function, you probably want (need?) to refactor.

Clean functions accomplish a single task!

DRY: Don’t Repeat Yourself

Refactoring Example: Chatbot¶

Clicker Question #1¶

How many “things” does this function accomplish?

A) 0 | B) 1 | C) 2 | D) 3 | E) 4+

import random 

def have_a_chat():
    """Main function to run our chatbot."""
    
    chat = True

    while chat:

        # Get a message from the user
        msg = input('INPUT :\t')
        out_msg = None
        
        # Check if the input is a question
        input_string = msg
        if '?' in input_string:
            question = True
        else:
            question = False

        # Check for an end msg 
        if 'quit' in input_string:
            out_msg = 'Bye!'
            chat = False
            
        # If we don't have an output yet, but the input was a question, 
        # return msg related to it being a question
        if not out_msg and question:
            out_msg = "I'm too shy to answer questions. What do you want to talk about?"

        # Catch-all to say something if msg not caught & processed so far
        if not out_msg:
            out_msg = random.choice(['Good.', 'Okay', 'Huh?', 'Yeah!', 'Thanks!'])

        print('OUTPUT:', out_msg)

have_a_chat()

INPUT :	hi
OUTPUT: Huh?
INPUT :	who are you?
OUTPUT: I'm too shy to answer questions. What do you want to talk about?
INPUT :	ok
OUTPUT: Okay
INPUT :	huh?
OUTPUT: I'm too shy to answer questions. What do you want to talk about?
INPUT :	quit
OUTPUT: Bye!

Refactored Example: Chatbot¶

What this function does:

takes an input
checks if input is a question
checks if input is supposed to end the chat
return appropriate response if question, end chat, or other

That’s four different things! Functions should do a single thing…

def get_input():
    """ask user for an input message"""
    
    msg = input('INPUT :\t')
    out_msg = None
    
    return msg, out_msg

def is_question(input_string):
    """determine if input from user is a question"""
    
    if '?' in input_string:
        output = True
    else:
        output = False
    
    return output

def end_chat(input_list):
    """identify if user says 'quit' in input and end chat"""
    
    if 'quit' in input_list:
        output = 'Bye'
        chat = False
    else:
        output = None
        chat = True
        
    return output, chat

def return_message(out_msg, question):
    """generic responses for the chatbot to return"""
        
    # If we don't have an output yet, but the input was a question, 
    # return msg related to it being a question
    if not out_msg and question:
        out_msg = "I'm too shy to answer questions. What do you want to talk about?"

    # Catch-all to say something if msg not caught & processed so far
    if not out_msg:
        out_msg = random.choice(['Good.', 'Okay', 'Huh?', 'Yeah!', 'Thanks!'])
        
    return out_msg

def have_a_chat():
    """Main function to run our chatbot."""
    
    chat = True

    while chat:

        # Get input message from the user
        msg, out_msg = get_input()
        
        # Check if the input is a question
        question = is_question(msg)
         
        # Check for an end msg 
        out_msg, chat = end_chat(msg)
       
        # specify what to return
        out_msg = return_message(out_msg = out_msg, question = question)
        
        print('OUTPUT:', out_msg)

have_a_chat()

INPUT :	hi
OUTPUT: Thanks!
INPUT :	how are you?
OUTPUT: I'm too shy to answer questions. What do you want to talk about?
INPUT :	python
OUTPUT: Thanks!
INPUT :	quit
OUTPUT: Bye

Project Notes¶

Write some code
Test to make sure it works
Check code style (naming, spacing, etc.)
Add documentation
Move to module (if necessary)
Add unit tests

Note on imports: If you want to be able to use modules (imports) within a module/script, be sure to import it at the top.

Introductory Python