Python 3.7.3 : Using the Pony python module.

The development team of the Pony project comes with this intro:
Using Pony object-relational mapper you can concentrate on writing the business logic of your application and use Python syntax for interacting with the database. Pony translates such queries into SQL and executes them in the database in the most efficient way.
The Pony python module can be installed on Python 2.7 or Python 3.
Today I tested with the Python 3.7.3 version:

C:\Python373>cd Scripts
C:\Python373\Scripts>pip install pony
Collecting pony
...
Successfully built pony
Installing collected packages: pony
Successfully installed pony-0.7.10

Let's start with one simple example:

C:\Python373>python.exe
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 21:26:53) [MSC v.1916 32 bit (Inte
l)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import pony
>>> from pony import orm
>>> from pony.orm import *
>>> mydb = Database()
>>> class Person(mydb.Entity):
...     name = Required(str)
...     surname = Required(str)
...     age = Required(int)
...     house = Set('Home')
...
>>> class Home(mydb.Entity):
...     owner = Required(Person)
...     address = Required(str)
...     floors = Required(int)
...     perimeter = Required(int)
...
>>> show(Person)
class Person(Entity):
    id = PrimaryKey(int, auto=True)
    name = Required(str)
    surname = Required(str)
    age = Required(int)
    house = Set(Home)
>>> show(Home)
class Home(Entity):
    id = PrimaryKey(int, auto=True)
    owner = Required(Person)
    address = Required(str)
    floors = Required(int)
    perimeter = Required(int)

Let's see the relationships of this example.
The house variable is set to the type named Home.
The owner variable has type Person.
The Pony supports 4 database types: SQLite, MySQL, PostgreSQL, and Oracle.
Use absolute path, see the error generated by bind function when saving it to the database file:

>>> mydb.bind(provider='sqlite', filename='err_my.sqlite', create_db=True)
...
ValueError: When in interactive mode, please provide absolute file path. Got: 'err_my.sqlite'

The correct way to bind the database is:

mydb.bind(provider='sqlite', filename='C:\\Python373\\mydb.sqlite', create_db=True)

Using the Pony python module with databases is simple to use, see the documentation webpage:

# SQLite
db.bind(provider='sqlite', filename=':memory:')
# or
db.bind(provider='sqlite', filename='database.sqlite', create_db=True)
# PostgreSQL
db.bind(provider='postgres', user='', password='', host='', database='')
# MySQL
db.bind(provider='mysql', host='', user='', passwd='', db='')
# Oracle
db.bind(provider='oracle', user='', password='', dsn='')

The next step is the mapping process for declared entities to the corresponding tables in the database, like: creates tables, foreign key references, and indexes if necessary:

>>> mydb.generate_mapping(create_tables=True)

Let's fill the database using these objects:

data001 = Person(name='John',surname = 'Unknown', age=18)
data002 = Person(name='Unknown',surname = 'Unknown', age=81)
add001 = Home(owner = data001,address = '18', floors = 1, perimeter=0)
add002 = Home(owner = data002,address = '11', floors = 0, perimeter=1)

These objects will be saved only after the commit function is called.

>>> commit()

Let's see the next steps:
- Writing queries:

>>> select (var_p for var_p in Person)

>>> select (var_p for var_p in Person)[:]
[Person[1], Person[2]]
>>> select (var_p for var_p in Person)[:].show()
id|name   |surname|age
--+-------+-------+---
1 |John   |Unknown|18
2 |Unknown|Unknown|81

- Getting objects:

>>> p1 = Person[1]
>>> print(p1)
Person[1]
>>> print(p1.name)
John

- Updating an object:

>>> m = Person.get(name='John')
>>> print(m.age)
18

Even I used an SQLite database, the databases can be used writing queries according to the databases

>>> x = 25
>>> Person.select_by_sql('SELECT * FROM Person p WHERE p.age < $x')
[Person[1]]

Instead of creating models manually, you can use the examples from the Pony distribution package:

>>> from pony.orm.examples.estore import *
...
SELECT "Product"."id", "Product"."name", "Product"."description", "Product"."pic
ture", "Product"."price", "Product"."quantity"
FROM "Product" "Product"
WHERE 0 = 1

COMMIT
COMMIT
PRAGMA foreign_keys = true
CLOSE CONNECTION
RELEASE CONNECTION

You can see the database diagram at the eStore webpage.
This tutorial can be continued with additional pieces of information and examples.
You can read more at Pony ORM webpage.