LangPy Usage Guide

Verify Installation

Verify that LangPy is correctly installed by running the command without arguments.

langpy

Basic Usage

Execute LangPy files directly

Create a file with the appropriate extension (.pyes for Spanish, .pypt for Portuguese, .pyfr for French) and execute it with the langpy command.

# hello.pyes
definir main():
    nombre = "World"
    imprimir(f"Hello {nombre}!")

main()

langpy hello.pyes

Supported Languages

The language is determined solely by the file extension

• Spanish: .pyes extension - keywords like definir, si, para, imprimir
• Portuguese: .pypt extension - keywords like definir, se, para, imprimir
• French: .pyfr extension - keywords like definir, si, pour, imprimer

Execute Projects

LangPy supports project structures with __main__ entry point

Organize your code in directories and use __main__.pyes as the main entry point.

my_project/
├── __main__.pyes          # Entry point
├── math.pyes        # Local module
└── utils/
    ├── __init__.pyes
    └── helpers.pyes

langpy my_project/

Transpile to Python

Convert LangPy files to standard Python files

Generate .py files that can be executed with the standard Python interpreter.

langpy transpile script.pyes

LangPy automatically resolves and transpiles all local imported modules with the corresponding language extension, preserving directory structure.

# If main.pyes imports utils/math.pyes:
# main.pyes → main.py
# utils/math.pyes → utils/math.py

Transpile to Specific Directory

Generate Python files in a custom output directory

Use the --output flag to specify an output directory. LangPy will copy all necessary files preserving the structure.

langpy transpile main.pyes --output dist/
langpy transpile main.pyes -o dist/

CLI Commands Reference

langpy <file>

Directly execute a LangPy file or project with __main__.pyes

langpy script.pyes
langpy my_project/

langpy transpile

Convert LangPy files to standard Python. Automatically resolves local LangPy imports.

langpy transpile script.pyes

--output / -o

Specify output directory for transpilation. Preserves directory structure and copies referenced vanilla .py files.

langpy transpile script.pyes --output dist/
langpy transpile script.pyes -o dist/

--force / -f

Force overwrite of existing .py files during transpilation.

langpy transpile script.pyes --force
langpy transpile script.pyes -f

--help

Display help information and available commands.

langpy --help

--version

Display the installed LangPy version.

langpy --version

Working with Libraries

LangPy is 100% compatible with Python libraries

You can import and use any Python library or create local modules using LangPy syntax.

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

analizar_datos()

langpy main.pyes

How It Works

LangPy is a lexical transpiler that only translates keywords to Python, leaving everything else unchanged.

1. Read your .pyes/.pypt/.pyfr file
2. Tokenize using Python's standard library tokenizer
3. Replace only NAME tokens with keywords (strings and comments remain unchanged)
4. Untokenize back to valid Python code
5. Execute with standard Python virtual machine