the37lab-database-tools 0.1.0

PostgreSQL database tools including DDL migration management and connection pooling

The37Lab Database Tools

A collection of PostgreSQL database utilities for Python, including DDL migration management and connection pooling.

Packages

This package contains two main modules:

ddl_manager

A PostgreSQL DDL migration management tool that tracks schema changes using APPLY/REVERT migration files. Provides both a CLI interface and programmatic API.

Features:

• File-based migration system using .ddl files
• Automatic validation of APPLY/REVERT file pairs
• Migration tracking in database
• Rollback support
• CLI and programmatic interfaces

See ddl_manager documentation for detailed usage.

postgres_pool

PostgreSQL connection pooling and database utilities with convenient abstractions for common database operations.

Features:

• Thread-safe connection pooling
• Database conversion utilities (DBConversion class)
• JSON column support
• Tag management helpers
• Post-insert hooks

Installation

From Source (Development)

pip install -e .

Regular Install

pip install .

Dependencies

• Python 3.7+
• psycopg2>=2.9.0

Quick Start

DDL Manager

from ddl_manager import DDLManager

manager = DDLManager(
    dsn="postgresql://user:password@host:port/database",
    ddl_directory="path/to/ddl/files"
)

# Check status
applied, unapplied = manager.status()

# Apply migrations
manager.update()

CLI Usage:

Set environment variables:

export POSTGRES_DSN="postgresql://user:password@host:port/database"
export DDL_DIRECTORY="path/to/ddl/files"

Then run:

ddl_manager status
ddl_manager update
ddl_manager log --json

Or use as a module:

python -m ddl_manager status

Postgres Pool

from postgres_pool import init_pool, get_connection, get_cursor, DBConversion

# Initialize the connection pool with DSN
init_pool("postgresql://user:password@host:port/database")

# Use connection pool
with get_connection() as conn:
    with get_cursor(conn) as cur:
        cur.execute("SELECT * FROM users")
        results = cur.fetchall()

# Use DBConversion for table operations
conv = DBConversion(
    table="users",
    cols=["id", "name", "email"],
    convs={},
    bools=[],
    autos=["id"]
)

with get_cursor() as cur:
    user = conv.select_id(cur, 1)
    new_user = conv.insert(cur, {"name": "John", "email": "[e-mail]"})

Environment Variables

DDL Manager

• POSTGRES_DSN: PostgreSQL connection string
• DDL_DIRECTORY: Path to directory containing DDL migration files

Postgres Pool

The connection pool must be initialized explicitly by calling init_pool(dsn) before use. No environment variables are required.

License

MIT

Development

Install development dependencies:

pip install -e ".[dev]"