миграции в Pyramid

Пример миграций в пирамиде:
В Django south в Pyramid alembic. Создаём файл alembic.ini и указываем путь до настроек :, т.е. <имя проекта>:<название папки> например hlp:alembic

pyramid.includes =
    pyramid_debugtoolbar
    pyramid_tm
    ziggurat_foundations.ext.pyramid.sign_in

ziggurat_foundations.model_locations.User = hlp.models.auth:User
#sqlalchemy.url = sqlite:///%(here)s/hlp.sqlite
sqlalchemy.url = postgresql://postgres:postgres@localhost:5432/hlp

# By default, the toolbar only appears for clients from IP addresses
# '127.0.0.1' and '::1'.
# debugtoolbar.hosts = 127.0.0.1 ::1

###
# wsgi server configuration
###

[server:main]
use = egg:waitress#main
host = 0.0.0.0
port = 6543

[alembic]
# path to migration scripts
script_location = hlp:alembic

в проекте создаем папку alembic со следующей структурой:

 alembic  tree
.
├── env.py
├── script.py.mako
└── versions
    └── 29ac938c56f_starting.py

env.py

from __future__ import with_statement
from alembic import context
from sqlalchemy import engine_from_config
from sqlalchemy.engine.base import Engine
from pyramid.paster import setup_logging

# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config

from hlp.models import Base

setup_logging(config.config_file_name)

engine = engine_from_config(config.get_section('app:main'), 'sqlalchemy.')

target_metadata = Base.metadata


def run_migrations_offline():
    """Run migrations in 'offline' mode.

    This configures the context with just a URL
    and not an Engine, though an Engine is acceptable
    here as well. By skipping the Engine creation
    we don't even need a DBAPI to be available.

    Calls to context.execute() here emit the given string to the
    script output.

    """
    context.configure(url=engine.url)

    with context.begin_transaction():
        context.run_migrations()


def run_migrations_online():
    """Run migrations in 'online' mode.

    In this scenario we need to create an Engine
    and associate a connection with the context.

    """

    if isinstance(engine, Engine):
        connection = engine.connect()
    else:
        raise Exception(
            'Expected engine instance got %s instead' % type(engine)
        )

    context.configure(
        connection=connection,
        target_metadata=target_metadata
    )

    try:
        with context.begin_transaction():
            context.run_migrations()
    finally:
        connection.close()

if context.is_offline_mode():
    run_migrations_offline()
else:
    run_migrations_online()

script.py.maco

"""${message}

Revision ID: ${up_revision}
Revises: ${down_revision}
Create Date: ${create_date}

"""

# revision identifiers, used by Alembic.
revision = ${repr(up_revision)}
down_revision = ${repr(down_revision)}

from alembic import op
import sqlalchemy as sa
${imports if imports else ""}

def upgrade():
${upgrades if upgrades else "pass"}


def downgrade():
${downgrades if downgrades else "pass"}

Создаем первую миграцию:

alembic revision --autogenerate -m "create table"

переходим к последней миграции:

alembic upgrade head

Есть ешё ништиковые команды типа:

 alembic upgrade +2
 alembic downgrade -1
 alembic upgrade 29ac
 alembic history
 alembic current

пример исключения таблиц из миграций http://blog.utek.pl/2013/ignoring-tables-in-alembic/


подробнее здесь https://alembic.readthedocs.org/en/latest/tutorial.html