petradb 1.5.0

Embeddable SQL database for Python — PostgreSQL-compatible, in-memory or persistent

petradb

Embeddable SQL database for Python — PostgreSQL-compatible, in-memory or persistent.

Wraps the PetraDB native shared library via ctypes. No compilation needed — just install the library and import.

Install

pip install petradb

Requires libpetradb-engine.so (Linux) or .dylib (macOS). Download from GitHub Releases and place in /usr/local/lib, or set PETRADB_LIB_PATH.

Quick Start

from petradb import Database

db = Database()  # in-memory

db.execute("""
    CREATE TABLE users (id SERIAL PRIMARY KEY, name TEXT NOT NULL, age INT);
    INSERT INTO users (name, age) VALUES ('Alice', 30), ('Bob', 25);
""")

for row in db.query("SELECT * FROM users ORDER BY name"):
    print(f"{row.id}: {row.name}, age {row.age}")

db.close()

Persistent Storage

db = Database('mydata.db')  # creates or opens

Context Manager

with Database() as db:
    db.execute("CREATE TABLE t (id INT)")
    rows = db.query("SELECT * FROM t")

Row Access

row = db.query_one("SELECT id, name FROM users WHERE id = 1")
row.name       # attribute access
row['name']    # dict-style access
row[0]         # index access
row.to_dict()  # {'id': 1, 'name': 'Alice'}

Cursor (Lazy Iteration)

with db.cursor("SELECT * FROM large_table") as cur:
    for row in cur:
        process(row)

User-Defined Functions

db.create_function('double', 1, lambda args: args[0] * 2)
db.query("SELECT double(age) FROM users")

Links

• Documentation
• C API Reference
• GitHub