pygarden 0.3.24

Package to perform everyday tasks - logging, accessing database, etc.

pyGARDEN Package

Code for the pyGARDEN (General Application Resource Development Environment Network) Python Package to include easy injectable and rich logging, environment checking, and database connections and query. By default, only SQLite is available as a mixin, but other mixin types to the Database class are Postgres ([postgres] extra) or Microsoft SQL Server ([mssql] extra). See the extras section for more information on how to install these extras, when to choose them, and how to use them. Some highlights from pyGARDEN:

• This package contains an extensible Database metaclass with a generic query function that is usable out of the box.
• Everything is configurable with environmental variables -- including email sending, logging, and database connections.

Installation

Installation via uv

If you have a uv venv, you can run the following command in the root of the repo:

uv pip install -e ".[dev,cli,postgres]"

You may then need to source your uv environment to use the pygarden command line interface, e.g. source .venv/bin/activate.

Replace the above extras with the extras of your choice.

Extras

To enable support for specific databases, use the following extras:

• postgres: Enables Postgres support via psycopg2
• mssql: Enables MSSQL support via pymssql

pymssql on MacOS

Before install the mssql extra, you may need to install freetds using brew:

brew install freetds openssl@3.0
export LDFLAGS="-L/opt/homebrew/opt/freetds/lib -L/opt/homebrew/opt/openssl@3.0/lib"
export CPPFLAGS="-I/opt/homebrew/opt/freetds/include -I/opt/homebrew/opt/openssl@3.0/include"
export PKG_CONFIG_PATH="/opt/homebrew/opt/openssl@3.0/lib/pkgconfig"

Then, install pymssql to your uv environment on its own using:

uv pip install pymssql==2.2.11 --no-binary :all:

After than, you can run uv sync --extra mssql or uv sync --extra all to get the rest of the dependencies in the group.

Installation via pip

Run this command to install version 0.3.24 (latest) via pip:

python3 -m pip --no-cache-dir install pygarden==0.3.24

This will install latest (not recommended):

python3 -m pip --no-cache-dir install pygarden

Getting the Image

The Docker image for this project is hosted on Savannah, and is tagged with savannah.ornl.gov/common/pygarden:${PYTHON_VERSION:-3.12}-latest, where ${PYTHON_VERSION:-3.12} is the Python version you want to use. To pull the image, you can run:

docker pull savannah.ornl.gov/common/pygarden:${PYTHON_VERSION:-3.12}-latest

Saving the Image to a Tar File

If you want to save the image to a tar file, you can run:

docker save savannah.ornl.gov/common/pygarden:${PYTHON_VERSION:-3.12}-latest -o pygarden.tar
gzip pygarden.tar  # optionally compress the tar file

Now you can transport the image wherever you'd like!

Configuration via Environment Variables

Below is a list of environmental variables and what they do:

• DATABASE_TIMEOUT, PG_TIMEOUT: an integer representing the seconds to wait before deciding a timeout occurred.
• DATABASE_DB, PG_DATABASE: a string representing the database to connect to
• DATABASE_USER, PG_USER: a string representing the user to connect to the database as
• DATABASE_PW, PG_PASSWORD: a string representing the password for the DATABASE_USER
• DATABASE_HOST, PG_HOST: a string representing the hostname or IP address hosting the database
• DATABASE_PORT, PG_PORT: an integer representing the port to connect to the database on
• DATABASE_SCHEMA, PG_SCHEMA: a string representing the schema to default to when creating a database connection

These environmental variables have been assigned default values for the Docker container in the file envfile, which is called in docker-compose.yaml and docker-compose.test.yaml

Creating an extensible Database Python Class

Some Database methods such as query and open rely on python mixins, which allow abstract classes to interact with different types of databases and provide additional functionality not provided by the Database class. Below is an example of how to create a Database class that uses the PostgresMixin:

from pygarden.mixins.postgres import PostgresMixin
from pygarden.database import Database


class PostgresDatabase(Database, PostgresMixin):
    """The class that allows Database to interact with psycopg2."""
    # TODO add additional functions for your class here, specific to your needs

with PostgresDatabase() as db:
    db.query('SELECT NOW()')

Creating a CRUD table with crud_table.py

from pygarden.mixins.postgres import PostgresMixin
from pygarden.database import Database
from pygarden.crud_table import CRUDTable

# PLEASE NOTE: the name of class MUST be consistent with the name of the
# table in the database itself.
class Users(CRUDTable):
    """Provides CRUD access to the users table"""
    def __init__(self, db):
    """__init__:

    :param db: the database that contains the 'users' table.
    """
    # be sure to define the columns as they appear in the database.
    # in this example, the users table has 6 columns.
    columns = {
        'id': int,
        'email': str,
        'password': str,
    }
    # initialize the super class with the column definition, the schema that
    # the table is in, and the database object.
    super().__init__(columns, schema='public', db)

    # TODO add additional functions for your class here, specific to your needs


class PostgresDatabase(Database, PostgresMixin):
    """The class that allows Database to interact with psycopg2."""
    def __init__(self):
        super().__init__()
        # here we are assigning the CRUD table to the database's 'users'
        # variable and passing the database object to the constructor
        self.users = users(self)
    # TODO add additional functions for your class here, specific to your needs

with PostgresDatabase() as db:
    db.query('SELECT NOW()')

    # this will create a user in the database, with the specified fields and
    # null for the columns not specified
    db.users.create(id=1337, email='[e-mail]', password='*****')

    # this will read the entire user's table 'SELECT * FROM public.users;'
    users_table = db.users.read()

    # this will read only id, and email columns from the users table
    # 'SELECT id, email FROM public.users;'
    columns_users_table = db.users.read(columns=['id', 'email'])

    # data can be read from the database in 'json' format by specifying
    # json=True in your call. The 'json' format returned is a python dictionary
    # that is json serializable
    json_data = db.users.read(json=True)

    # where clauses can be passed as keyword arguments to the call
    # 'SELECT * FROM public.users WHERE id = 1337;
    filtered_users_table = db.users.read(id=1337)

    # to update entries, a where clause must be passed as follows
    # 'UPDATE public.users SET email='[e-mail]' WHERE id=1337;'
    db.users.update(where={'id': 1337}, email='[e-mail]')

    # to delete entries, a where clause must also be passed. The where clause
    # for a deletion should come in the form of keyword arguments
    # 'DELETE FROM public.users WHERE id=1337;'
    db.users.delete(id=1337)

Testing

The tests for pygarden use pytest and are available in the dev extra.