PythonRuns

Tests on Python Code Examples.

A collection of small, self-contained Python scripts and proofs of concept: formatting and language features, file and image utilities, SQLite/PostgreSQL persistence with Tkinter UIs, calls to public Brazilian government APIs, JWT handling and more. Each example is a standalone module under pythonruns/src/mytests/, runnable on its own with python -m.

Table of Contents

• What's Inside
• Tech Stack
• Prerequisites
• Installation
• How to Run
• Running Tests
• Project Structure
• Latest Articles, Publications and Tech-Talks
• Author
• License

What's Inside

All examples live in pythonruns/src/mytests/.

Language basics and formatting

• calculate_power.py: calculate a power x^y of a number.
• float_format.py: tests and prints multiple float formats.
• boolean_number.py: converting numbers to booleans.
• sort_list.py: sorting a list of numbers ascending and descending.
• switch_case.py: match/case statement driven by console input.
• input_console.py: reading values from the console and combining and/or conditions.
• future/with_future.py and future/without_future.py: effect of from __future__ import annotations on __annotations__.
• app_logging.py: the basics of logging in Python.
• happy_teacher_day.py: prints a heart in the console with the word Teachers, for happy teachers day.
• I_love_you.py: prints a heart in the console with a given 8-character word.

Files, text and data

• camel_2_snake_case.py: converts a file text content from camel case to snake case.
• split_files.py: splits a text input file (like a log) into a given number of chunks.
• convert_pdf_to_docx.py: converts a pdf file to a docx file.
• fake_data.py: creates fake test data using Faker.
• short_uuid.py: generates short UUIDs and converts standard UUIDs with shortuuid.
• pickle/pickle_serialize_load.py: serializing and loading objects with pickle.
• progress_bar.py: console progress bars with progress and tqdm.
• plot_graph.py: sin/cos/tan subplots with Matplotlib and NumPy.

Images and QR codes

• remove_background.py: removes background from images, letting only the main subject.
• resize_images.py and compress_images.py: resize/compress image files down to a target size in KB.
• qrcode/generate_qrcode.py: creates a QR-Code from your data.
• qrcode/generate_qrcode_with_midle_empty.py: QR code with a transparent hole in the center for a logo.

Databases (Tkinter UIs)

• database/save_to_mem_db.py, persist_json_in_memory.py, persist_json_to_db.py, persist_json_to_db_visualize.py, persist_json_disk_to_db_visualize.py: storing and viewing JSON data in memory or an in-memory SQLite database through a Tkinter window.
• database/persist_with_postgres.py: the same idea backed by PostgreSQL via psycopg2 (requires a running PostgreSQL instance).

Public APIs, security and ops

• jusbr/call_api_fines_ibama_brazil.py: Environmental fines research in Brazil's government site.
• jusbr/call_api_tjmg.py, call_api_trf_proc.py, call_api_trf_classe_orgao.py: queries against the CNJ DataJud public API (by process number, or by class/court body).
• jwt_test.py: JWTManager class to create and decode JWT tokens with python-jose.
• backup_restore_wordpress.py: backup/restore of a WordPress site (database and files) between a local machine and a remote server over SSH/SFTP with paramiko.

Tests

• tests/mytests/test_jwt_manager.py: pytest suite for JWTManager (token creation, decoding, expiry, invalid signatures, multiple HMAC algorithms).
• tests/test_examples.py: unittest check of OS path separators.

The scripts/ folder holds standalone shell/Python utilities (server install, disk cleanup, git helpers, app monitoring) that are not part of the package.

Tech Stack

• Python 3.11 / 3.12 (requires-python = ">=3.11,<3.13"), managed with uv
• pytest, pytest-cov, pytest-html
• Main libraries used by the examples: Faker, python-jose, pdf2docx, Pillow, rembg, OpenCV, qrcode, Matplotlib, NumPy, pandas, requests, paramiko, psycopg2, shortuuid, tqdm, progress
• Code quality: ruff, black, isort, mypy, pre-commit
• CI: GitHub Actions (ci.yml) running tests on Python 3.11 and 3.12

Prerequisites

• Python 3.11 or 3.12
• uv
• Tkinter (bundled with most Python installs) for the database/ examples
• A PostgreSQL instance only for persist_with_postgres.py

Installation

This project uses uv for fast and reliable Python package management.

Installing uv

If you don't have uv installed yet:

# On macOS and Linux
curl -LsSf https://astral.sh/uv/install.sh | sh

# On Windows
powershell -c "irm https://astral.sh/uv/install.ps1 | iex"

# Or with pip
pip install uv

Setting up the project

Create and activate a virtual environment, then install dependencies:

# Create a virtual environment and install dependencies (one step)
uv sync

# Or manually:
# 1. Create a virtual environment
uv venv

# 2. Activate it
# On Linux/macOS:
source .venv/bin/activate
# On Windows:
# .venv\Scripts\activate

# 3. Sync all dependencies
uv sync

Alternatively, you can use the provided makefile:

make install

Working with uv

Common uv commands:

# Sync dependencies from uv.lock (recommended for consistent environments)
uv sync

# Sync with all dependency groups (including dev)
uv sync --all-groups

# Update dependencies and regenerate lockfile
uv lock --upgrade
uv sync

# Add a new dependency
# (Edit pyproject.toml, then run:)
uv lock
uv sync

# Run a command in the virtual environment
uv run python -m pythonruns
uv run pytest

# Use pip if needed for one-off packages (not recommended for project deps)
uv pip install package-name

How to Run

Run any example as a module from the repository root:

uv run python -m pythonruns.src.mytests.fake_data
uv run python -m pythonruns.src.mytests.jwt_test
uv run python -m pythonruns.src.mytests.split_files /path/to/app.log 5

The general form is:

python3 -m pythonruns.src.mytests.file_to_run

Some examples read from resources/ and write to output/ using relative paths (../resources, ../output), so check the paths at the top of a script before running it.

Running Tests

# Run all tests (same command as CI)
uv run pytest tests/ -v

# With coverage (HTML report in ./htmlcov)
uv run pytest tests/ --cov=pythonruns --cov-report=html

# Or via the makefile (requires the virtual environment to be activated)
make test

Other makefile targets: make help lists them all (install, sync, update, pre-commit, build, clean, ...).

Project Structure

PythonRuns/
├── pythonruns/
│   ├── hello_world.py
│   └── src/mytests/        # example modules (database/, future/, jusbr/, pickle/, qrcode/, ...)
├── tests/                  # pytest / unittest tests
├── resources/              # sample inputs (images, sample.pdf)
├── output/                 # generated outputs (images, CSV, docx)
├── scripts/                # standalone shell/Python utilities
├── docs/                   # uv migration notes and quick reference
├── pyproject.toml          # project metadata and dependencies
├── uv.lock
└── makefile

📝 Latest Articles, Publications and Tech-Talks

• [Code & Coffee - Substack] Java turns 30: An Innovation Journey Through Time and Technology - What 30 years of Java can teach us about building tech that lasts. A timeline on what happened to Java from May 23rd 1995, when Sun Microsystems introduced Java 1.0 to the world, until modern days that made Java essentially great.
• [Dev Community] FastAPI Unleashed: Building Modern and High-Performance APIs - Demostranting FastAPI, a web framework designed for building APIs quickly and efficiently. Python based natively async, it takes advantage of non-blocking I/O to handle high loads, with extra features such as embedded data validation with Pydantic and auto-documentation with Swagger/Redoc.
• [Dev Community] NoSQL Fighters Arena: The Battle of Data Titans - Explore NoSQL databases reimagined as superheroes, each with unique powers and weaknesses, in a fun and visual battle-style format.
• [LinkedIn Pulse] Java is turning 30 soon! Here's Why You Should Care, Even if You're Not a Tech Person - Java is a super famous programming language, and it is almost turning 30. But wait, what exactly is Java, and why should it matter to you?
• [DZone] Top NoSQL Databases and When to Use Each - A practical guide comparing NoSQL technologies like MongoDB, Cassandra, Redis, and more, highlighting their strengths, limitations, and best use cases.
• [Dev Community] Test Python Code Like a Pro with Poetry, Tox, Nox and CI/CD - Improving your test coverage with multiple python versions through the use of of tools like Poetry, Pytest, Tox, Nox and CI/CD.
• [Dev Community] Python Multithreading: Unlocking Concurrency for Better Performance - The essentials of Python multithreading with practical examples and best practices to enhance application performance through concurrency. A must-read, to understand threading application performance in deep.
• [DZone] Secure Password Hashing in Java: Best Practices and Code Examples - Secure password hashing using modern algorithms like BCrypt, Argon2, and PBKDF2 with salting and computational intensity for better security, as alternative to SHA-512.
• More available on my LinkedIn page.

Author

• Wallace Espindola, Sr. Software Engineer / Solution Architect / Java & Python Dev
• LinkedIn: linkedin.com/in/wallaceespindola/
• GitHub: github.com/wallaceespindola
• E-mail: wallace.espindola@gmail.com
• Twitter: @wsespindola
• Gravatar: gravatar.com/wallacese
• Dev Community: dev.to/wallaceespindola
• DZone Articles: DZone Profile
• Pulse Linkedin: LinkedIn Articles
• Website: W-Tech IT Solutions
• Substack: wallaceespindola.substack.com
• Medium: medium.com/@wallaceespindola
• Slides: speakerdeck.com/wallacese

License

• This project is released under the Apache 2.0 License.
• See the LICENSE file for details.
• Copyright © 2025 Wallace Espindola.