print out schema from sqlalchemy

create_table_from_sqlalchemy.py

import argparse
import inspect

from importlib import import_module

from sqlalchemy import create_engine
from sqlalchemy.schema import CreateTable

from skim.slxmodels.meta import BaseModel


def _pred(m):
    """Extract the models
    """
    try:
        return issubclass(m, BaseModel) and m != BaseModel
    except TypeError:
        return False


def _table_for_model(model, engine):
    table_sql = CreateTable(getattr(model, '__table__'))
    return str(table_sql), str(table_sql.compile(engine))


def parse_arguments():
    parser = argparse.ArgumentParser(description='model')

    parser.add_argument('-f', '--file',
                        help='Full path to the the models file, for example skim.slxmodels.currencies.models',
                        required=True)

    parser.add_argument('-m', '--model',
                        help='model to produce the SQL for')

    parser.add_argument('--db_url', required=True)

    return parser.parse_args()


def main():
    ns = parse_arguments()
    models = import_module(ns.file)
    engine = create_engine(ns.db_url)
    
    res = {}
    if ns.model:
        mod = getattr(models, ns.model)
        res[mod.__name__] = _table_for_model(mod, engine)
    else:
        for m in inspect.getmembers(models, predicate=_pred):
            mod = getattr(models, m[0])
            res[mod.__name__] = _table_for_model(mod, engine)

    for table_name, (agnostic, specific) in res.items():
        print("-- Creating table name {}".format(table_name))
        print(specific)


if __name__ == '__main__':
    main()