Plain meanings for the words that come up in the slides and the tutorials. If a word on a slide is not here, ask — it will be added.
| Word | What it means |
|---|---|
| repository (repo) | A folder that git is watching. Your assignment is one; the course material is one. |
| commit | A saved version of the folder, with a short message saying what changed. |
| push | Send your commits to GitHub. Pull brings down what changed there. |
| clone | Download a whole repo, with its history, to your machine. |
| branch | A parallel version of the same repo. The course repo has 2026 (this year) and 2025 (last year). |
| fork | Your own copy of somebody else's repo, under your account. |
| pull request (PR) | "I changed something in my copy — please take it into yours." |
| issue | A note on a repo: a bug, a question, something unclear. |
| README.md | The file GitHub shows on a repo's front page. .md is markdown: text with a little formatting. |
| organisation (org) | A shared GitHub account for a group. Ours is sd5913. Being a member is not the same as being allowed to write to a repo. |
| the registry | pfad.ait4x.org — where your GitHub account is matched to your student ID. |
| Word | What it means |
|---|---|
| terminal | The window where you type commands instead of clicking. In VS Code: Ctrl+`` (the key top-left, under Esc). |
| script | A file of Python. schotter.py is a script. |
| run | Make the computer carry out a script, top to bottom. uv run schotter.py. |
| uv | The tool that runs Python scripts and fetches what they need. The only Python command we type. |
| library (package) | Code somebody else wrote, that your script imports. pygame is one. |
| dependency | A library your script needs. A script should say what it needs at the top. |
| environment | The Python and the libraries a script runs with. If it is not written down, the script only works on your machine. |
| console (REPL) | A place to type one line of Python at a time and see the answer. On the slides: press the ` key. |
| output | What a program prints or draws when it runs. |
| error (traceback) | Python's report of what went wrong and on which line. Read it from the bottom. |
| Word | What it means |
|---|---|
| syntax | The spelling and grammar of code. Wrong syntax: the program does not start. |
| variable | A name for a value. size = 24 makes a variable called size. |
| type | What kind of value something is: a whole number (int), a number with a decimal point (float), text (str), yes/no (bool), a list, a dict. |
string (str) |
Text. The quotes are what make it text: "3" is text, 3 is a number. |
| list | Several things in order: [3, 1, 4]. Positions count from 0. |
| dict (dictionary) | Values you look up by name: {"name": "Ada"}. |
boolean (bool) |
True or False. What a comparison like a > b gives you. |
| loop | Do something once for each item: for w in range(size):. |
| condition | A yes/no test that decides what happens: if bar or cap:. |
| function | A named piece of code you can call: print(...), abs(...), or one you define with def. |
| return | What a function hands back. A function with no return gives back None. |
| None | Python's word for "nothing here". |
| indentation | The spaces at the start of a line. In Python they say what belongs inside a loop, a condition, a function. Four spaces. |
| state | Something a program remembers from one step to the next. last_square_empty is state. |
| random | A number the program picks by chance. The same seed gives the same random numbers again. |
| tuple | A short list you do not change, written with round brackets: (hour, height). A coordinate is one. |
| enumerate | Loop over a list and get the position as well as the value: for hour, height in enumerate(heights, start=1):. |
| comprehension | A loop written on one line that collects the answers: [move(p, 10, 20) for p in shape]. |
| Word | What it means |
|---|---|
| data | Numbers somebody measured and published. The tide at Quarry Bay, every earthquake of the last month. |
| JSON | A common file format for data: lists and dicts, written out as text. Every number in it is text until you say float(). |
| CSV | A file of rows and columns, separated by commas. Opens in Excel, reads in three lines of Python. |
| API (endpoint) | An address you fetch data from instead of a web page. data.weather.gov.hk/...?station=QUB is one. |
| parse | Turn a file of text into lists and numbers your program can use. |
| cache | Fetch once, save the raw reply into data/, then read the saved file. Your script then runs with no internet, and the repo still works when the address moves. |
| scrape | Take numbers off a web page that was not meant to be read by a program. A page is a tree; BeautifulSoup walks it. |
| User-Agent | The line your script uses to say who it is when it fetches something. Say who you are, and do not fetch in a loop. |
| plot | Draw numbers as a picture. matplotlib is the library we use for it. |
| axis | One direction of a picture, and what it means: hour across, metres up. An unlabelled axis is a picture nobody can read. |
| vector | A list of numbers where each position means something: (hour, height), (lng, lat), (knot, deg). Swap them and the picture is nonsense. |
| transformation | A rule that turns one vector into another: move, scale, rotate, or hour-and-height into angle-and-radius. A chart type is a transformation. |
| matrix | A small table of numbers that is a transformation. Matplotlib, CSS and p5.js all call it transform. |
| polar | Saying where a point is with an angle and a distance instead of x and y. to_xy converts one to the other. |
| projection | The transformation that puts a round world on a flat page. Longitude across, latitude up is the cheapest one. |
| frame | One picture of an animation. An animation is a function of which frame it is: def frame(i). |
| Word | What it means |
|---|---|
| interface | The part of a program a person can see and use. |
| input | Information or an action a person gives the program. |
| state | Something a program remembers between actions, such as a selected month or current count. |
| event | Something that happens, such as a click, key press, or completed request. |
| callback | A function the program runs when an event happens. |
| client | A program that asks a service for information or an action. A browser can be a client. |
| server | A program that receives requests and sends responses. |
| frontend | The part of an app a person uses. It can be a Streamlit page or HTML and JavaScript in a browser. |
| backend | The part that handles requests and data. The Week 4 FastAPI service runs on a Cloudflare Worker. |
| HTTP | The web protocol clients use to send requests and receive responses. |
| request | A message a client sends to a server, asking for data or an action. An HTTP request can include a method, path and query. |
| response | What a program sends or shows after an input. In a web request, it is the reply the server sends. |
| API | A set of rules and endpoints one program offers for another program to use. |
| endpoint | An address and method a web service responds to, such as GET /tides. |
| origin | A web page's scheme, host and port, such as https://sd5913.github.io; the page path is not part of it. |
| JSON (web response) | A text format commonly used to send structured data between a service and a client. |
| CORS | A browser rule: a server lists which other origins may read its response. It does not sign a user in or make an API private. |
| static site | HTML, CSS and JavaScript files served to the browser; the site itself does not run Python on each request. GitHub Pages can host one. |
| Streamlit | A Python library for building small web apps; changing a widget reruns the script. |
| FastAPI | A Python framework that connects HTTP endpoints to functions, validates inputs, and creates an interactive API docs page. |
| GET / POST | HTTP methods: GET asks to read a resource; POST sends information for the service to process, such as an image prompt. |
| Base64 | A way to encode bytes as text. The image API can put a PNG into JSON this way; decode it to save the image. |
| API key | A secret a program sends to identify itself to a service. Keep it in a server environment, outside browser code and Git. |
| session state | Values Streamlit keeps available across reruns in one browser session. |
| test | A repeatable check of whether code meets one stated expectation. |
| assertion | A statement in a test that must be true, such as response.status == 200. |
| red test | A test that fails because the feature it describes is not implemented yet. |
| green test | A test that passes after the code implements the expected behavior. |
| fixture | Small, known input used by a test so the result is predictable. |
| unit test | A test of one small piece of code, separated from the network and other outside systems. |
| integration test | A test that checks connected parts together, such as making an HTTP request to the real API and checking its response. |
| test case | One example of an input and the result a test expects. |
| test-driven development (TDD) | Write one test first, see it fail, add the code, then run it again and see it pass. |
| GitHub Actions | GitHub's service for running a workflow when an event such as a push happens. |
| workflow | A YAML file that tells GitHub Actions what event starts a job and which steps to run. |
| workflow_dispatch | A GitHub Actions event that lets someone start a workflow manually. |
| Word | What it means |
|---|---|
| spec (specification) | A sentence about what the program must do, that is either true or false. "A cap never sits under a drawn cell." |
| bug (fault) | Code that runs but does the wrong thing. |
| predict | Say what the output will be before you run it. |
| diff | The lines that differ between two versions of a file. GitHub shows one on every commit. |
| check (a workflow) | A program GitHub runs on your repo every time you push, that ends in a green tick or a red cross. |
| SVG | A picture described as text — lines, shapes, coordinates. A script can write one. |