LangPy 0.2.0

Write Python using your native-language keywords

LangPy

Learn and write Python code in Spanish, French, Portuguese (more coming soon) 🌍

LangPy is a lexical transpiler that lets you learn and write Python code using natural language keywords in Spanish (español), French (français), Portuguese (português), soon more - perfect for beginners and non-English speakers. Write si instead of if, para instead of for, with zero runtime overhead.

# ejemplo.pyes (Spanish)
definir saludar(nombre):
    si nombre == "Ana":
        imprimir("Hola Ana")
    sino:
        imprimir("Hola", nombre)

saludar("Luis")

$ langpy ejemplo.pyes
Hola Luis

Why LangPy?

LangPy makes Python more accessible to non-English speakers and complete beginners by allowing you to use natural language keywords. It's designed to help you focus on learning programming logic in your native language, while making it trivial to migrate to vanilla Python later - no additional tools or new concepts required, just rename your keywords when you're ready.

What LangPy IS ✅

• A lexical transpiler that translates keywords to Python
• 100% compatible with Python libraries and tools
• Zero runtime overhead - executes as native Python
• Easy migration path back to pure Python

What LangPy is NOT ❌

• NOT a new programming language
• NOT a custom interpreter or VM
• NOT translating error messages or APIs
• NOT changing Python's semantics

If something crosses these boundaries, it's out of scope.

Quick Start

Installation

Requirements: Python 3.10+

pip install langpy

📚 Official Documentation - Complete guides, tutorials, and API reference

Your First Program

Create a file hello.pyes:

definir main():
    nombre = "World"
    imprimir(f"Hello {nombre}!")

main()

Run it:

langpy hello.pyes

That's it! LangPy transpiles your code to standard Python and executes it immediately.

Supported Languages

Language	Extension	Keywords Example
Spanish	.pyes	para, si, sino, imprimir
French	.pyfr	pour, si, sinon, imprimer
Portuguese	.pypt	para, se, senao, imprimir

The language is determined solely by the file extension. No flags or configuration needed.

Real-World Example

LangPy works seamlessly with local imports and external libraries.

operations.pyes

definir suma(a, b):
    retornar a + b

definir resta(a, b):
    retornar a - b

main.pyes

desde operations importar suma, resta
importar numpy como np

definir analizar_datos():
    # Use your functions
    resultado = suma(10, 5)
    imprimir(f"Suma: {resultado}")

    # Use any Python library
    datos = np.array([1, 2, 3, 4, 5])
    imprimir(f"Media: {np.mean(datos)}")

analizar_datos()

Run it:

langpy main.pyes

Project Structure Support

LangPy supports Python-style package structures with __main__ entry points:

mi_proyecto/
├── __main__.pyes          # Entry point
├── operations.pyes        # Local module
└── utils/
    ├── __init__.pyes
    └── helpers.pyes

Execute the entire project:

langpy mi_proyecto/

Use Cases

• 🎓 Learning Python - Focus on programming logic in your native language
• 🌍 Teaching - Teach Python to non-English speaking students
• 🔄 Gradual Migration - Start in your language, migrate to English Python later
• 🛠️ Prototyping - Quick scripts without mental translation overhead
• 📚 Educational Content - Create programming tutorials in local languages

How It Works

.pyes / .pypt / .pyfr file
        ↓
tokenize (Python stdlib)
        ↓
keyword replacement
        ↓
untokenize
        ↓
execute with Python VM

Key Design Principles

• Only NAME tokens are translated (keywords)
• Strings and comments remain unchanged
• Attribute names are preserved (obj.method)
• No custom AST or parser
• If Python can't tokenize it, neither can LangPy

CLI Usage

Execute directly

# Run a file
langpy script.pyes

# Run a project directory (requires __main__.pyes)
langpy my_project/

Transpile to Python

# Transpile in place (generates .py next to .pyes, resolves LangPy imports)
langpy transpile script.pyes

# Transpile to specific directory (resolves LangPy imports + copies vanilla .py files)
langpy transpile main.pyes --output dist/
langpy transpile main.pyes -o dist/  # short form

The transpile command:

• Always resolves and transpiles all local LangPy imports
• With --output: additionally copies referenced vanilla .py files (excludes pip modules)
• Preserves directory structure in output

Extract (single-file mode)

For tooling integration (IDE extensions, linters):

# Extract to specific file
langpy extract input.pyes --output build/output.py

# Extract to directory (uses input filename)
langpy extract input.pyes --output build/
langpy extract input.pyes -o build/  # short form

The extract command transpiles a single file without resolving imports - useful for development tools.

Force overwrite

langpy transpile script.pyes --force
langpy transpile script.pyes -f  # short form

Get help

langpy --help
langpy --version

Project Status

Version: 0.2.0

• ✅ Stable transpilation core
• ✅ Language lexicons defined
• ✅ Project structure support (__main__ entry points)
• ✅ Import resolution and tree transpilation
• ✅ Output directory support with structure preservation
• ✅ Comprehensive test suite
• ✅ Clear project scope

Contributing

LangPy's lexicon system is modular, making it easy to add new languages without modifying the core. Want to add your language? We'd love to have you contribute!

License

MIT

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Made with ❤️ for the global Python community