inspect.py

from sqlalchemy import Table, MetaData, create_engine
from sqlalchemy.engine import reflection

# Configurações de conexão abstraídas em variáveis de ambiente setadas num arquivo .env
DB_USER = os.getenv('DB_USER')
DB_PASS = os.getenv('DB_PASS')
DB_HOST = os.getenv('DB_HOST')

DB_NAME = os.getenv('DB_NAME')
SQLALCHEMY_DATABASE_URL = f"postgresql+psycopg2://{DB_USER}:{DB_PASS}@{DB_HOST}:5432/{DB_NAME}"

engine = create_engine(SQLALCHEMY_DATABASE_URL)


def get_equivalent(typename):
    # tipo do Postgres: tipo do SQLAlchemy
    types = {
        'VARCHAR': 'String',
        'TIMESTAMP': 'DateTime',
        'BIGINT': 'Integer',
        'NUMERIC': 'Float'
    }
    return types.get(typename, typename.title())


def create_class_source(class_name, table_name):

    meta = MetaData()
    table_text = """class {}(Base):\n""".format(class_name.title().replace("_",""))
    table_text += """    __tablename__ = '{}' \n\n""".format(table_name)
    table = Table(table_name, meta, autoload_with=engine)
    for column in table.columns:
        col_text = """    {name} = Column({type}, {{extras}})\n""".format(
            name=column.name, 
            type=get_equivalent(
                repr(column.type).strip('()')
            ),
        )
        extras = ""
        # neste ponto inspecionar os atributos de column em que estiver interessado
        # e montar a string extras com alguns 'if' - 
        # ex.: ( column.foreign_keys, column.primary_key)
        table_text += col_text.format(extras=extras)
    return table_text + "\n\n"