OIM3640 - Problem Solving and Software Design

2024 Fall

Session 15 (10/21)

Today's Agenda

• Welcome/News/Announcements
• Introduction to API
• Lectures
  • Data Structures in Python
    • Tuples and Sets
    • Choosing the right one
  • Text Analysis
    • Introducing Assignment 2

Welcome/News/Announcements

• Next class:
  • Introducing Project
  • Quiz 4 on Data Structures/APIs
• Communications
  • Meet with me in person during office hours at least once this semester.
  • Email - specify course # in subject title, e.g., "OIM3640: GitHub settings"
  • Use Slack/GitHub when asking code-related questions
• Questions?

What we have learned so far...

• Variables, Expressions, Statements
• Types: int, float, string, boolean, Nonetype, string, list, dictionary
• Functions
• Conditional Statements: if...elif...else
• Iterations: for, while
• Pseudo-code

API (Application Programming Interface)

• An API is a set of protocols, tools, and standards for building software applications, that allows different applications to communicate with each other.

• Example: Let's say you want to know the current price of Bitcoin

  • Human: Opens a browser, searches "Bitcoin price", and checks websites.
  • Computer: Sends a request to an API and gets Bitcoin price in JSON format.
    • Example API endpoint: https://api.coindesk.com/v1/bpi/currentprice.json

API Example: OpenWeather

• Create an API key from https://openweathermap.org/api
• Download the sample code, weather.py, from resources/code
• Use the urllib.request library to send HTTP requests to the OpenWeather API and retrieve data in JSON format
• Remember to protect sensitive data (e.g., API keys, API tokens, passwords)
  • Create .env file and store your API key, e.g., OPENWEATHER_API_KEY=...
  • Install python-dotenv in Terminal: python -m pip install python-dotenv

  • import os
    from dotenv import load_dotenv
    
    load_dotenv()
    APIKEY = os.getenv("OPENWEATHER_API_KEY")
    

  • Add .env to the .gitignore to prevent committing it to a public repository.

Recommendations on API

• What is an API? In English, please.

• Rapid API Comics

• YouTube - What is an API and how does it work? (In plain English)

Data Structures in Python

• List
• Dictionary
• Tuple
• Set
• When to Use What
  • Sequences of sequences

Choosing Data Structures

• Programs often have to work with many objects of various types. For example:
  • A portfolio of stocks
  • A table of stock prices
  • A collection of customer orders
• Main choices:
  • list: ordered data, access by index
  • tuple: ordered data, immutable, access by index
  • dict: (normally treated as) unordered data, access by key
  • set: unordered collection of unique items

Considerations when Choosing Data Structures

• Data order:
  • Do you need to maintain the order of elements?
• Mutability:
  • Do you need it to be mutable (changeable) or immutable (fixed)?
• Fast access:
  • Do you need fast access to elements by key or index?
• Uniqueness:
  • Do you need to ensure that elements are unique within the collection?

Session 15

• Case - Text Analysis
• Download following file(s) from OIM3640/resources/code/data to data folder
  • Pride and Prejudice.txt
• Download following file(s) from OIM3640/resources/code/ to session15 folder
  • analyze_book.py

Assignment 2 - Text Analysis Project

• Due 10/30 Wednesday
• To get started:
  • Fork the base repository to your GitHub account.
  • Clone the forked repository to your computer.
• To submit:
  • Push all the code and update the README.md file in your GitHub repository.
  • Create a pull request from your forked repository to the upstream repository.
  • Submit the URL of your project's GitHub repository to Canvas.
• Please Start early!