This document provides an overview of the BandersnatchStarter project, designed for someone with minimal Python experience, primarily familiar with Jupyter notebooks in a data science context. The goal is to help you understand the project’s structure, technical stack, key files, and concepts, along with pointers to resources for learning. The project is a Flask-based web application for working with monster data, creating visualizations, and building machine learning models. It’s structured as a series of sprints to guide you through the development process.
The BandersnatchStarter project is a data science and machine learning application focused on "monster data." It involves setting up a database, creating interactive visualizations, and building a machine learning model. The project is beginner-friendly for those with notebook experience, as it uses familiar Python libraries like pandas and scikit-learn, but introduces web development concepts with Flask and MongoDB.
- Sprint 1: Database Operations - Set up a MongoDB database and manage monster data.
- Sprint 2: Dynamic Visualizations - Create interactive charts using Altair.
- Sprint 3: Machine Learning Model - Build and integrate a predictive model using scikit-learn.
- Flask: A lightweight Python web framework to create web applications. Think of it as a way to turn your Python code into a website.
- MongoDB: A NoSQL database that stores data as JSON-like documents, unlike the tabular data you’re used to in pandas.
- Altair: A Python library for creating interactive visualizations, similar to plotting in notebooks but for web display.
- Scikit-learn: A machine learning library you may have used in notebooks for models like regression or classification.
The repository is organized into folders that align with the sprints:
/(root): Contains the splash page (main landing page of the web app)./data: Stores tabular monster data, likely as CSV files or database collections./view: Contains code for dynamic visualizations (charts/graphs)./model: Houses the machine learning model code./app: Likely contains the Flask application code (e.g.,main.py).- Other key files:
requirements.txt: Lists Python libraries needed for the project..env: Stores sensitive data like the MongoDB connection string (not committed to GitHub).install.shandrun.sh: Scripts for macOS/Linux to install dependencies and run the app.
- The root folder contains the Flask app’s entry point (
app/main.py), which sets up routes (URLs) for different pages, like the splash page. - The data folder is where you’ll interact with MongoDB or CSV files, similar to loading data in a notebook with
pandas.read_csv(). - The view folder is for visualization code, where you’ll use Altair to create charts, like plotting in notebooks but rendered on a webpage.
- The model folder contains machine learning code, similar to scikit-learn workflows in notebooks (e.g., loading data, training a model, making predictions).
The project uses the following technologies, with explanations for beginners and links to beginner-friendly resources.
| Component | Description | Docs/Guides |
|---|---|---|
| Python3 | The programming language used for logic. Familiar from notebooks. | Python Docs |
| Flask | A web framework to create the website. Handles routing (e.g., /home URL) and rendering HTML pages. |
Flask Quickstart |
| Jinja2 | A templating engine for Flask to create dynamic HTML pages. Think of it as filling placeholders in HTML with Python data. | Jinja2 Docs |
| HTML5 | Markup language for structuring web pages. | W3Schools HTML |
| CSS3 | Styling for web pages (e.g., colors, layouts). | W3Schools CSS |
| MongoDB | A NoSQL database for storing monster data as JSON-like documents. | MongoDB Getting Started |
| Altair | A Python library for creating interactive visualizations, similar to seaborn or matplotlib but web-friendly. | Altair Tutorial |
| Scikit-learn | A machine learning library for building models (e.g., classification, regression). Familiar from data science notebooks. | Scikit-learn Tutorials |
| Render.com | A platform for deploying the web app online. | Render Python Guide |
- Flask vs. Notebooks: In notebooks, you run cells to see outputs. In Flask, you write Python code that responds to web requests (e.g., visiting a URL triggers a function).
- MongoDB vs. pandas: Instead of loading a CSV into a DataFrame, you’ll query MongoDB to get data as JSON, which you can convert to a DataFrame.
- Altair vs. matplotlib: Altair creates interactive charts that work in browsers, unlike static matplotlib plots in notebooks.
Here’s a breakdown of important files (based on typical Flask project structure) and what they do, with hints for understanding their role.
| File/Folder | Purpose | Conceptual Hints |
|---|---|---|
app/main.py |
The main Flask application file. Defines routes (URLs) and how the app responds to user requests. | Look for @app.route() decorators, which map URLs (e.g., /) to Python functions. Similar to defining functions in a notebook but for web pages. |
requirements.txt |
Lists Python libraries (e.g., Flask, pymongo, altair) needed to run the project. | Like installing packages in a notebook with !pip install, but done via pip install -r requirements.txt. |
.env |
Stores sensitive data like MongoDB connection strings. | Keep this file private (not on GitHub). Use the python-dotenv library to load it in your code. |
data/ |
Contains data files (e.g., CSVs) or scripts to interact with MongoDB. | Similar to loading a CSV in a notebook, but you may use pymongo to query MongoDB. |
view/ |
Contains visualization code, likely using Altair. | Think of this as your plotting code in a notebook, but the output is rendered in HTML. |
model/ |
Contains machine learning code, likely using scikit-learn. | Similar to a notebook where you load data, preprocess it, and train a model with fit(). |
templates/ |
Folder for HTML templates (used with Jinja2). | These are HTML files with placeholders (e.g., {{ variable }}) filled by Python data. |
static/ |
Folder for CSS, JavaScript, or images. | Like adding styles to a plot, but for the entire webpage. |
- app/main.py: This is the heart of the Flask app. It might look like:
This code sets up a route for the homepage (
from flask import Flask, render_template app = Flask(__name__) @app.route('/') def home(): return render_template('index.html')
/) and renders an HTML template. - data/: Might include a script to load monster data into MongoDB, like:
This is like adding rows to a DataFrame but in a database.
from pymongo import MongoClient client = MongoClient('mongodb://...') db = client['monsters'] db.collection.insert_one({'name': 'Bandersnatch', 'power': 100})
- view/: Might include an Altair chart, like:
This is like plotting in a notebook but saves the chart for web display.
import altair as alt import pandas as pd data = pd.DataFrame({'power': [100, 200], 'name': ['Bandersnatch', 'Jabberwock']}) chart = alt.Chart(data).mark_bar().encode(x='name', y='power') chart.save('chart.html')
Here are key programming concepts and functions you’ll encounter, with explanations for beginners.
-
Flask Routes (
@app.route())- What it does: Maps a URL (e.g.,
/data) to a Python function that returns a webpage or data. - Example: A route might fetch monster data from MongoDB and display it in a table.
- Hint: Think of routes as functions that run when you visit a webpage, like clicking a cell in a notebook.
- Docs: Flask Routing
- What it does: Maps a URL (e.g.,
-
MongoDB Queries (
pymongo)- What it does: Retrieves or saves data in MongoDB, similar to filtering a DataFrame.
- Example:
db.collection.find()gets all monster documents, likedf[df['power'] > 100]. - Hint: Use
pymongoto connect to MongoDB and query data. Convert results to a DataFrame for familiar manipulation. - Docs: PyMongo Tutorial
-
Altair Visualizations (
alt.Chart)- What it does: Creates interactive charts for the web, like matplotlib but browser-friendly.
- Example: A bar chart of monster powers, rendered in HTML.
- Hint: Use pandas DataFrames as input, like in notebooks, and save charts as HTML or JSON.
- Docs: Altair Basic Example
-
Scikit-learn Models (
fit(),predict())- What it does: Trains a machine learning model and makes predictions, like in a notebook.
- Example: A classification model to predict if a monster is "dangerous" based on features.
- Hint: Load data from MongoDB or CSV, preprocess it with pandas, and use scikit-learn’s familiar API.
- Docs: Scikit-learn Getting Started
-
Set Up the Environment
- Follow the README’s instructions to create a virtual environment and install dependencies (
pip install -r requirements.txt). - If you’re new to virtual environments, think of them as isolated notebooks where libraries don’t conflict with other projects.
- Resource: Python Virtual Environments
- Follow the README’s instructions to create a virtual environment and install dependencies (
-
Run the App Locally
- Use
python -m app.main(Windows) or./run.sh(macOS/Linux) to start the app. - Visit
http://127.0.0.1:5000in your browser to see the app, like viewing a notebook’s output. - Hint: If you get errors, check if all dependencies are installed and the
.envfile has the correct MongoDB URL.
- Use
-
Explore the Code
- Start with
app/main.pyto see how routes are defined. - Check
data/for database scripts,view/for visualization code, andmodel/for machine learning code. - Hint: Treat each folder like a section of a notebook (data loading, plotting, modeling).
- Start with
-
Work on Sprints
- Sprint 1: Focus on MongoDB setup and basic queries. Practice inserting and retrieving monster data.
- Sprint 2: Create simple Altair charts, like bar or scatter plots, using sample data.
- Sprint 3: Build a basic scikit-learn model, starting with a simple dataset (e.g., monster features like power, speed).
- Resource: Break each sprint into small tasks, like cells in a notebook, to make it manageable.
- Python Basics: Python for Everybody (free course for beginners).
- Flask for Data Scientists: Flask Tutorial for Beginners (explains Flask with a data science focus).
- MongoDB for Beginners: MongoDB University (free courses on MongoDB basics).
- Altair for Visualizations: Altair Beginner’s Guide (explains data and plotting).
- Scikit-learn for ML: Scikit-learn User Guide (covers common ML tasks).
The README lists stretch goals (e.g., using Plotly instead of Altair, FastAPI instead of Flask). For beginners:
- Focus on the core sprints first.
- If you’re curious, explore one stretch goal, like adding a database reset function, which is similar to clearing and reloading a DataFrame.
- Resource: FastAPI Docs or Plotly Python for stretch goals.
- Treat the project like a notebook: break tasks into small, testable pieces (e.g., load data, plot one chart, train a simple model).
- Use the provided scripts (
install.sh,run.sh) to simplify setup, but understand what they do (like runningpip installor starting Flask). - If stuck, check error messages in the terminal, just like debugging a notebook cell, and refer to the linked docs.
Happy coding, and enjoy building your Bandersnatch project!