Python Practice

Python Tutor

Generate a Jupyter notebook filled with practice challenges and questions. Challenges cover pandas (data manipulation, cleaning, exploration, time series) and algorithms (vanilla Python data structures, sorting, searching, recursion).

Follow the rules in RULES.md.

Workflow

1. Gather parameters using AskUserQuestion. Ask the user:

   • Category: Which category to focus on, or generate a random mix from all categories. Present the subcategories listed below.
   • Difficulty: easy, medium, or hard.
   • Number of questions: How many challenges to include (default 10).
   • Output directory: Where to save the notebook. Default is notebooks/practice.
   • Previous exercises folder (optional): Path to a folder containing previous practice notebooks. If provided, scan these notebooks to avoid repeating exact questions. You may generate the same type of question but must vary the data, parameters, or scenario to ensure uniqueness.

2. Check for previous exercises (if folder provided):

   • Scan notebooks in the previous exercises folder for question prompts.
   • Extract the core challenge type from each (e.g., "filter DataFrame by condition", "implement binary search").
   • When generating new questions, avoid repeating the exact same prompt. You may reuse the same question type but must change the data, column names, values, or scenario to make it fresh.

3. Generate varied question data using the helper scripts (see Scripts below). For every notebook:

   • Run random_tickers.py to pick a fresh set of tickers for the session.
   • Run fetch_price_data.py to get real market data for those tickers. Use the --format code or --format returns flag to get a Python snippet you can embed in the notebook setup cell.
   • Run random_data.py to generate random numbers, date ranges, or messy DataFrames as needed by the questions.
   • Vary the data in each question so notebooks are never identical.

4. Build the notebook using generate_notebook.py:

   • Option A — from the question bank: Use --bank to pull pre-written questions and randomize:

     python scripts/generate_notebook.py \
       --bank questions/bank.json \
       --category pandas --difficulty easy --count 5 \
       --output notebooks/practice
     

   • Option B — custom questions: Generate a JSON array of question objects and pipe to the script:

     python scripts/generate_notebook.py \
       --category pandas --difficulty medium \
       --output notebooks/practice < /tmp/questions.json
     

   • Each question object must have prompt (str) and solution (str). Optional fields:
     • hint (str, will be rendered in a collapsed <details> tag). Hints must be hidden by default.
     • setup (str, per-question code cell), subcategory (str).

5. Customize the setup cell — replace the template's sample data with the real market data fetched in step 3. Use the output of fetch_price_data.py --format code or --format returns as the setup cell content.

6. Confirm the notebook path to the user when finished.

Notebook Structure

Each generated notebook must follow this structure:

1. Title cell (markdown): includes category, difficulty, date, and number of questions.
2. Setup cell (code): import statements and sample datasets. For pandas notebooks, embed real market data fetched with fetch_price_data.py.
3. For each question:
   • A markdown cell with the challenge prompt, numbered (e.g. "### Challenge 1"). Include:
     • A clear problem statement
     • Any sample data or expected output
     • When appropriate include a hidden hint wrapped in a <details><summary>💡 Hint</summary>...</details> tag (initially collapsed).
   • An empty code cell for the user to write their solution.
   • A hidden solution cell wrapped in a markdown <details><summary>✅ Solution</summary>...</details> tag so the user can reveal it.

Scripts

All scripts live in scripts/ and are run from that directory.

generate_notebook.py

Builds a .ipynb file from a category template + question data. Uses nbformat.

# From question bank:
python scripts/generate_notebook.py --bank questions/bank.json \
  --category pandas --subcategory series --difficulty easy --count 5 --output notebooks/practice

# From a JSON file of custom questions:
python scripts/generate_notebook.py --questions /tmp/my_questions.json \
  --category algorithms --difficulty hard --output notebooks/practice

# From stdin:
cat questions.json | python scripts/generate_notebook.py --category pandas --output notebooks/practice

random_tickers.py

Pick random ticker symbols to use in questions. Avoids repeating the same tickers.

python scripts/random_tickers.py --count 4                  # 4 random tickers
python scripts/random_tickers.py --count 3 --sector tech    # from tech sector
python scripts/random_tickers.py --count 5 --diverse        # one per sector
python scripts/random_tickers.py --list-sectors              # show all sectors

Use this every time you generate a notebook to ensure fresh ticker sets.

fetch_price_data.py

Fetch real stock price data from Yahoo Finance via yfinance. Embed the output in notebook setup cells so students work with real market data.

# Get a code snippet to embed in the notebook
python scripts/fetch_price_data.py --tickers AAPL MSFT TSLA --period 6mo --format code

# Get daily returns as a code snippet
python scripts/fetch_price_data.py --tickers AAPL MSFT --period 3mo --format returns

# Random tickers + real data
python scripts/fetch_price_data.py --random 4 --period 1y --format code

# Save as CSV
python scripts/fetch_price_data.py --tickers SPY QQQ --start 2023-01-01 --end 2024-01-01 --output prices.csv

random_data.py

Generate random numbers, date ranges, names, and messy DataFrames for question variety.

python scripts/random_data.py --type integers --count 10 --min 1 --max 100
python scripts/random_data.py --type floats --count 5 --min -0.05 --max 0.05
python scripts/random_data.py --type date_range --start 2020-01-01 --periods 30 --freq B
python scripts/random_data.py --type names --count 8
python scripts/random_data.py --type messy_dataframe --rows 20

Use --type messy_dataframe to generate data-cleaning exercises with realistic problems (missing values, inconsistent casing, whitespace, bad types, duplicates).

Templates

Category-specific notebook templates live in templates/. Each template provides:

• A title cell with {{difficulty}}, {{date}}, {{count}}, {{subcategories}} placeholders
• A setup cell with appropriate imports and sample datasets

Question Bank

Pre-written questions are stored in questions/bank.json. The bank is organized as:

{ category: { subcategory: { difficulty: [question, ...] } } }

Each question has: prompt, solution, and optionally hint and setup.

Categories and Subcategories

Pandas

Refer to references/PANDAS_NOTE.md for the topic tree and references/PANDAS_FOR_DATA_SCIENCE.md for functions and techniques. Use examples/PANDAS_EXAMPLES.md for sample data patterns.

Subcategories:

• Series: creation, retrieval, modification, alignment, built-in methods
• DataFrames: retrieval (loc/iloc, slicing, boolean masks), modification, column operations
• Data exploration: apply/applymap, correlations, covariance, DataFrame-Series arithmetic
• Missing data: detection, dropping, filling, interpolation
• Reindexing and sorting: reindex, drop, sort_index, sort_values
• Categorical data: unique values, value_counts, isin, dummy variables
• File I/O: reading/writing CSV, Excel, pickle
• Multi-indexing: multi-index DataFrames and Series, stack/unstack, swaplevel
• Time series: timestamps, offsets, date ranges, resampling, shifting
• GroupBy, pivot, merge: groupby, pivot_table, merge/join, concat
• Rolling and quantiles: rolling windows, qcut, shift for returns
• Plotting: line, bar, scatter, histograms, heatmaps with seaborn

Algorithms

Focused on vanilla Python (no external libraries).

Subcategories:

• Data structures: lists, dicts, sets, tuples, deques, heaps
• Sorting: bubble, merge, quick, insertion sort implementations
• Searching: linear search, binary search
• Recursion: factorial, fibonacci, tree traversal, divide and conquer
• String manipulation: reversal, palindromes, anagrams, pattern matching
• Math and logic: primes, GCD, modular arithmetic, bit manipulation

Difficulty Levels

• Easy: Single-concept problems. Provide hints and sample data. Expect 1-5 lines of code per solution.
• Medium: Combine 2-3 concepts. Provide sample data but no hints. Expect 5-15 lines of code.
• Hard: Multi-step problems requiring chaining operations or designing algorithms. No hints. Expect 10-30+ lines of code.

Additional Resources

• For pandas topic details, see references/PANDAS_NOTE.md
• For pandas functions reference, see references/PANDAS_FOR_DATA_SCIENCE.md
• For numpy context, see references/NUMPY.md
• For code examples and sample data, see examples/PANDAS_EXAMPLES.md