pony

library0.7.19pypypi✓ verified 87d ago

Pony ORM is a Python Object-Relational Mapper that allows developers to work with databases using Python objects and queries written in plain Python. It translates Python queries into optimized SQL, supporting SQLite, PostgreSQL, MySQL, and Oracle. The current version is 0.7.19. Releases occur periodically, often driven by new Python version support or significant bugfixes, indicating an active but not rapid development cadence with several months to a year between minor releases.

database

pip install pony

github ↗package ↗homepage ↗docs ↗

INSTALL

IMPORT

SIG · PONY

pony

databasepythonv0.7.19

Install

1.8s avg

Import

245ms

Disk

20MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.7.19 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.920 runs

installs and imports cleanly · install 0.0s · import 0.256s · 21.2MB

glibc

py 3.10–3.920 runs

installs and imports cleanly · install 1.8s · import 0.233s · 22MB

20MB installed

● package 20MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Database

✓ from pony.orm import Database

Required

✓ from pony.orm import Required

Optional

✓ from pony.orm import Optional

Set

✓ from pony.orm import Set

PrimaryKey

✓ from pony.orm import PrimaryKey

db_session

✓ from pony.orm import db_session

select

✓ from pony.orm import select

This quickstart demonstrates defining a database connection, creating entity models, generating the database schema, and performing basic CRUD operations within a `db_session` context. It uses an in-memory SQLite database for simplicity.

from pony.orm import * db = Database() class Person(db.Entity): id = PrimaryKey(int, auto=True) name = Required(str) age = Optional(int) cars = Set('Car') class Car(db.Entity): make = Required(str) model = Required(str) owner = Required(Person) db.bind(provider='sqlite', filename=':memory:', create_db=True) db.generate_mapping(create_tables=True) @db_session def create_data(): p1 = Person(name='John Doe', age=30) c1 = Car(make='Toyota', model='Camry', owner=p1) p2 = Person(name='Jane Smith', age=25) print("Data created.") @db_session def query_data(): for p in select(p for p in Person if p.age < 35): print(f"Name: {p.name}, Age: {p.age}") for car in p.cars: print(f" Car: {car.make} {car.model}") create_data() query_data()

Debug

Known issues

breakingPony ORM 0.7.17 dropped support for Python versions older than 3.8. Users on Python 3.7 or earlier must either upgrade their Python environment or use an older Pony ORM version (e.g., 0.7.16 or earlier).

fix

Upgrade Python to 3.8+ or pin Pony ORM to a compatible version.

affects: <0.7.17

breakingPony ORM versions prior to 0.7.15 were incompatible with Python 3.10+ due to reliance on the deprecated `parser` module. Attempting to use older versions on Python 3.10+ will result in import errors.

fix

Upgrade Pony ORM to version 0.7.15 or newer for Python 3.10 and above.

affects: <0.7.15

gotchaAll database operations (entity creation, updates, queries) must occur within an active `db_session`. Forgetting to use the `@db_session` decorator or `with db_session():` context manager will lead to `TransactionError` or `ObjectIsFreedException`.

fix

Always wrap database interactions within a `db_session`.

affects: All versions

gotchaPony ORM's unique query language uses generator expressions (e.g., `select(p for p in Person if p.age < 35)`). New users often try to use SQL strings or SQLAlchemy-style expressions, which will not work as expected.

fix

Familiarize yourself with Pony's Pythonic query syntax as described in the official documentation.

affects: All versions

Errors

Common errors & fixes

TransactionError: An attempt to work with detached object

Trying to access or modify Pony ORM entities outside of an active `db_session` context.

fix

Wrap your database operations within a `with db_session():` block or decorate functions with `@db_session`.

TypeError: DBAPIProvider.__init__() got multiple values for argument 'database'

An internal bug in Pony ORM versions prior to 0.7.16, specifically affecting `db.bind()` calls with certain argument combinations.

fix

Upgrade Pony ORM to version 0.7.16 or newer. This bug was resolved in that release.

OperationalError: (2013, 'Lost connection to MySQL server during query')

Network instability, database server restart, or connection timeouts for long-running processes that hold open connections.

fix

While Pony ORM includes some reconnection logic, ensure each logical unit of work is encapsulated within a `db_session`. For very long-running applications, consider explicit connection management or shorter `wait_timeout` on the database.

AttributeError: module 'pony.orm.parser' has no attribute 'suite'

Using Pony ORM older than 0.7.15 with Python 3.10+. Python 3.10 removed the `parser` module which older Pony versions relied upon.

fix

Upgrade Pony ORM to version 0.7.15 or newer, which transitioned to using Python's standard `ast` module.

Upgrade

Version history

0.7.19latest on PyPI · released Aug 27, 2024

Audit

Dependencies

No dependency data recorded yet.

Agent activity

9 hits · last 30 days

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Resources

githubhttps://github.com/ponyorm/pony ↗

packagehttps://pypi.org/project/pony/ ↗

homepagehttps://ponyorm.com ↗

docshttps://docs.ponyorm.org ↗