Intro

Want to train a model without installing a hulking IDE or writing a separate script for every experiment? Jupyter notebooks let you mix runnable code, notes, and pretty plots in one share‑able file. In this guide we’ll spin up a notebook, load data, build a logistic regression classifier, and visualize the results. No sweat!

tldr; We’ll install Jupyter with pip, crack open a notebook, wrangle a CSV in pandas, train & evaluate a scikit‑learn model, and chart its performance. All inside a single .ipynb. You’ll finish with a repeatable workflow you can fork for any ML idea.

Setting Up / Prerequisites

• Python ≥ 3.9 (use pyenv or the official installer)
• pip or conda package manager
• Virtual environment (e.g., python -m venv venv or conda create -n ml-jupyter python=3.11)
• A terminal with git (optional, for dataset download)
• The following Python packages:

pip install jupyterlab pandas scikit-learn matplotlib seaborn

Why Jupyter Rocks (and How to Use it Well)

Jupyter isn't just a place to run Python. It's a digital lab notebook built for messy, iterative exploration. You don't have to write a full script before running your code. Instead, you write and run cells one at a time, keeping results visible as you go.

Tip: Think of each cell as a test tube: Mix something new, see what happens, make notes, then move on.

Some key notebook best-practices:

• Break work into small cells - Each step (importing, loading data, preprocessing, training, etc.) should be its own cell. This helps with debugging and lets you rerun only the parts you need.
• Use markdown cells to narrate - Don't just write code, explain it! You can use markdown cells to add headings, lists.... Markdown and even LaTeX math for formulas.
• Restart & run all often - Use Kernal -> Restart Kernal and Run All Cells to ensure your notebook runs from top to bottom.
• Name your notebooks clearly - Use descriptive names like edh-staple-classifier.ipynb so you can find them later.

Implementation Steps

Launch Jupyter

Before you write a single line of Python you need a notebook server running. jupyter lab boots up a lightweight web server on localhost:8888 (or the next free port) and opens your default browser. From here every notebook lives in the directory you launched the command from, so start it at the root of your project folder.

Tip: If you prefer the classic interface, swap lab for notebook. Add --port 9000.

jupyter lab # or: jupyter notebook

Create a Notebook

In the Jupyter UI choose File → New → Notebook and select Python 3. A new tab appears with an empty code cell and an auto‑generated filename like Untitled.ipynb. Rename it to something memorable (e.g., edh-staple-classifier.ipynb) so future‑you can find it quickly.

Note: Every notebook is tied to a kernel. A kernal is an active Python process that keeps variables in memory between cell runs.

Import Libraries

Your first code cell should gather every library you’ll need. Keeping imports together makes it easier to debug missing packages and rerun the whole notebook end‑to‑end. Notice we pull in matplotlib before seaborn; the latter piggybacks on the former for plotting.

import pandas as pd
from sklearn.model_selection import train_test_split
from sklearn.linear_model import LogisticRegression
from sklearn.metrics import classification_report, confusion_matrix
import matplotlib.pyplot as plt
import seaborn as sns

Tip: Add %reload_ext autoreload and %autoreload 2 if you’re developing helper modules alongside the notebook. Jupyter will hot‑reload them on every cell run.

Load & Inspect Data

Jupyter automatically renders pandas DataFrames as slick HTML tables, so a simple df.head() becomes an instant mini‑dashboard. Always eyeball the first few rows and call df.info() to catch missing values or wonky dtypes before you train.

df = pd.read_csv('cards.csv') # sample MTG card dataset
display(df.head())
df.info()

Gotcha: If your CSV lives on the web, read it directly with pd.read_csv('https://...')—no download step required!

Pre‑process Features

Feature engineering is where ML wins or loses. Here we cherry‑pick three already‑encoded columns and split the data 80/20 into training and test sets. Setting random_state locks in determinism so a colleague can reproduce your exact split.

X = df[['mana_value', 'type_encoded', 'color_identity_encoded']]
y = df['is_edh_staple']
X_train, X_test, y_train, y_test = train_test_split(
    X, y, test_size=0.2, random_state=42, stratify=y
)

Tip: Use stratify=y when your classes are imbalanced to preserve the same positive/negative ratio in both splits.

Train the Model

Logistic regression is fast, interpretable, and perfect for a binary “staple or not” task. Crank max_iter up if the default 100 iterations fails to converge.

model = LogisticRegression(max_iter=1000)
model.fit(X_train, y_train)

Heads‑up: After training, check model.coef_ to see which features push predictions higher or lower—handy for blog post anecdotes.

Evaluate Performance

Next we generate a classification report and plot a confusion matrix. The heatmap gives an at‑a‑glance view of false positives vs false negatives.

preds = model.predict(X_test)
print(classification_report(y_test, preds))

cm = confusion_matrix(y_test, preds)
plt.figure(figsize=(4, 4))
sns.heatmap(cm, annot=True, fmt='d', cbar=False)
plt.xlabel('Predicted')
plt.ylabel('Actual')
plt.title('Confusion Matrix')
plt.show()

Note: If recall is more valuable than precision for your use‑case, focus on the lower row of the matrix.

Iterate & Document

Notebooks shine at rapid experimentation. Duplicate a cell, tweak a hyper‑parameter, rerun, and stash results in a Markdown cell for future reference.

Workflow tip: Use nbdime to diff notebook versions in git or adopt the new .ipynb text‑based format (jupyter nbconvert --to markdown) for readable PRs.

## Experiment 002 — Added stratification, accuracy +3.2 %

Next Steps

• Swap in more powerful algorithms (RandomForest, XGBoost).
• Perform hyper‑parameter tuning with GridSearchCV.
• Use JupyterLab extensions like variable inspector or nbdime for diffing.
• Export your notebook to HTML or Markdown for sharing (File → Export).
• Push it to a GitHub repo and enable Binder for one‑click reproducibility.

Outro

Thanks for reading! If this guide levelled up your ML workflow, pass it on to your fellow data dabblers or drop a comment with what you built. Until next time. Happy modelling!