sqlean-stubs

Type hints for sqlean.py - Python's sqlite3 + extensions.

Installation

pip install sqlean-stubs

or with uv:

uv add sqlean-stubs

Usage

Type hints enable IDE autocomplete and type checking for sqlean code:

from typing import Optional
import sqlean

def main_sqlean():
    print("Hello from try-sqlean-stubs!")
    conn: sqlean.Connection = sqlean.connect(":memory:")
    cursor: sqlean.Cursor = conn.cursor()

    # Create repos table
    cursor.execute("""
        CREATE TABLE repos (
            id INTEGER PRIMARY KEY,
            package_name TEXT NOT NULL,
            github_url TEXT NOT NULL
        )
    """)

    # Insert test data
    cursor.execute(
        "INSERT INTO repos (package_name, github_url) VALUES (?, ?)",
        ("sqlean.py", "https://github.com/nalgeon/sqlean.py")
    )
    cursor.execute(
        "INSERT INTO repos (package_name, github_url) VALUES (?, ?)",
        ("sqlean-stubs", "https://github.com/kracekumar/sqlean-stubs")
    )

    # Query the table
    cursor.execute("SELECT * FROM repos")

    # fetchone() returns Optional[Any]
    row: Optional[sqlean.Row] = cursor.fetchone()
    if row is not None:
        print(f"ID: {row[0]}, Package: {row[1]}, URL: {row[2]}")

    # User-defined functions
    def double(x: int) -> int:
        return x * 2

    conn.create_function("double", 1, double)
    conn.close()

if __name__ == "__main__":
    main_sqlean()

Benefits:

• IDE autocomplete and navigation
• Catch type errors before runtime with mypy or ty
• Better code documentation and refactoring safety

Features

• Complete type hints for Connection, Cursor, and Row objects
• Support for custom factories and row factories
• Type hints for user-defined functions and aggregates
• Callbacks support (authorizer, progress handler, trace callback, busy handler)
• Window function support
• Extensions management API
• Compatible with mypy, ty, pyright, and other type checkers

Requirements

• Python 3.9 or later
• pip, uv, or pipx for installation

---

Contributing

Development Setup

git clone https://github.com/nalgeon/sqlean-stubs.git
cd sqlean-stubs
uv sync

Running Tests

# Run all tests
uv run pytest tests/

# Linting
uv run ruff check .

# Type checking
uv run mypy tests/test_mypy.py
uv run ty check

# Test multiple Python versions (3.9-3.14)
uv run tox

Project Structure

• sqlean/dbapi2.pyi - Main DB-API 2.0 interface
• sqlean/extensions.pyi - Extension management API
• sqlean/py.typed - PEP 561 marker file
• tests/test_types.py - Runtime tests
• tests/test_mypy.py - Type checking tests

Adding Type Hints

1. Update the .pyi stub file
2. Add runtime test in tests/test_types.py
3. Add type checking test in tests/test_mypy.py
4. Run pytest tests/, mypy tests/test_mypy.py, and ty check

Code Style

• Follow PEP 484 for type hints
• Use Optional[X] instead of X | None (Python 3.9 compatibility)
• Use Literal types for constrained values
• Include docstrings for complex types

Before Submitting

uv run ruff check .
uv run pytest tests/ -v
uv run mypy tests/test_mypy.py
uv run ty check

License

Zlib (same as sqlean.py)