OIM3640 - Problem Solving and Software Design

2025 Spring

Session 04 (1/30)

Today's Agenda

• Welcome/News/Announcements
• Class Review
  • Quick Quiz
  • More about f-strings
• Lecture
  • Types

Welcome/News/Announcements

• Class GitHub:
  • Resources (including code templates): OIM3640/resources
  • Demo code (same as your oim3640 repo): OIM3640/oim3640
  • Slides: https://oim3640.github.io
• 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?

Keeping Up with Each Chapter

• Read the chapter after every class, regardless of whether we finish it in class.
• Create a separate .py file for that chapter and re-run all the demo code.
  • Experiment with variations or create derivations from the examples.
  • Ask "what if" questions.
  • Take notes as you experiment.
  • If you're stuck, ask ChatGPT or post your questions on Slack.
• Pre-read the next chapter before class, making note of anything you think might be challenging or interesting.

How to Ask Questions via Slack/GitHub/Email

• What were you trying to do?
  • The problem and context.
• What did you do?
  • Any relevant code snippets, or GitHub link to the code.
• What did you expect to happen?
• What actually happened?
  • Screenshots or descriptions of any strange behavior or errors.
  • Any relevant debug console or terminal output, such as error messages.

What we have learned so far...

• Basic operations of software:
  • VS Code
  • GitHub
• Python Basics:
  • Variables
  • Expressions
  • Statements

Quick Quiz

1. What is the shortcut to open Command Palette in VS Code?
2. What functions have we used/seen?
   • print(), input(), ...
3. Is increase perc a valid variable name?
4. Is file a valid variable name?
5. What is the output?

   x = 123
   y = x
   x = 'abc'
   print(y)
   

6. When using f-string, how do we justify the strings to the right?

Resources: f-string formatting in Python

• Python F-Strings Number Formatting Cheat Sheet
• Python 3's f-Strings: An Improved String Formatting Syntax (Guide)
• Python String Format Cookbook

More Questions

Whenever we learn a new feature, we should try it out and make errors on purpose to see what goes wrong.

1. We’ve seen that n = 42 is valid. What about 42 = n?
2. How about x = y = 1?
3. In some languages every statement ends with a semi-colon, ;. What happens if you put a semi-colon at the end of a Python statement?
4. What if you put a period . at the end of a statement?
5. In math notation you can multiply x and y like this: xy. What happens if you try that in Python?

Exercises

• All feedback will be provided in the GitHub Issues section of your oim3640 repo.
  • Regularly check the Issues section on your GitHub repository.
  • Reply if further discussion is needed.
  • Reply with evidence and close the issue if you believe it is resolved.
• If you have any question regarding class content/demo code
  • Create New issue in OIM3640/oim3640
    
  • or create new discussion

Programming Suggestions

• File/folder names
  • Use lowercase, i.e., session03
  • Use underscore, i.e., demo_types.py
• Add comments properly,
  • unless the code is self-explanatory.
  • Read: Real Python - Writing Comments in Python (Guide)
• Use descriptive and meaningful variable names, i.e., radius = 5
• Whenever possible, please use f-strings for printing the results.

Debugging

• Alt + Shift + F (or ⌥ Option + Shift + F on MacOS)
• Always read the error message and try to understand it.
• Pylance (in VS Code) is very helpful

Lecture

• 03 - Types