License

Licensing is important. This project uses BSD 3-clause license, and adds no other dependencies to your project (it does use a few things during build & testing) - that’s about as simple, safe, and free to use as it gets.

For more information check the LICENSE -file.

Basic usage

Firstly you’ll need this package in your project. Pick one of these:

pip install -U migrate-anything
poetry add migrate-anything
pipenv install migrate-anything

Simply put, create a Python package, don’t be too clever and call it e.g. migrations. Then put files in that package:

# migrations/__init__.py
from migrate_anything import configure, CSVStorage

configure(storage=CSVStorage("migration_status.csv"))

# migrations/01-initialize-db.py
# Please note that this is built for a completely hypothetical DB layer
from my_db import get_db

DB = get_db()

def up():
    DB.create_table("example")

def down():
    DB.delete_table("example")

This would configure your migrations’ status to be stored in a local file called migration_status.csv and set up your first migration script. If you have a my_db module that works like this you could just run this with a single command:

migrate-anything migrations
poetry run migrate-anything migrations
pipenv run migrate-anything migrations

Now in the real world you might want something more durable and a realistic example, so here’s e.g. what you’d do when using MongoDB:

# __init__.py
from migrate_anything import configure, MongoDBStorage
import pymongo

db = pymongo.MongoClient().my_db

configure(storage=MongoDBStorage(db.migrations))

# 01-initialize-db.py
from pymongo import MongoClient

client = MongoClient()
db = client.my_db

def up():
    db.posts.insert_one({
        "id": "post-1",
        "title": "We're live!",
        "content": "This is our first post, yay."
    })
    db.posts.create_index("id")

def down():
    db.posts.drop()

This would configure storage to a my_db.migrations MongoDB collection.

Command line flags

# Revert the last migration using migration code file.
migrate-anything migrations --revert-latest

Custom storage engines

Writing your own custom storage engine is easy.

# __init__.py
from migrate_anything import configure


class CustomStorage(object):
    def __init__(self, file):
        self.file = file

    def save_migration(self, name, code):
        with open(self.file, "a", encoding="utf-8") as file:
            file.write("{},{}\n".format(name, code))

    def list_migrations(self):
        try:
            with open(self.file, encoding="utf-8") as file:
                return [
                    line.split(",")
                    for line in file.readlines()
                    if line.strip()  # Skip empty lines
                ]
        except FileNotFoundError:
            return []

    def remove_migration(self, name):
        migrations = [
            migration for migration in self.list_migrations() if migration[0] != name
        ]

        with open(self.file, "w", encoding="utf-8") as file:
            for row in migrations:
                file.write("{},{}\n".format(*row))


configure(storage=CustomStorage("test.txt"))

You can also check out the examples.