Modify `SQLModel` to use snake case table names by default. [Credit @nuno-andre: https://github.com/fastapi/sqlmodel/issues/159#issuecomment-1142901416]

sql_modle_snake_case_table_names.py

from sqlmodel import SQLModel as _SQLModel
from sqlalchemy.orm import declared_attr

from functools import partial
import re


_snake_1 = partial(re.compile(r"(.)((?<![^A-Za-z])[A-Z][a-z]+)").sub, r"\1_\2")
_snake_2 = partial(re.compile(r"([a-z0-9])([A-Z])").sub, r"\1_\2")


def snake_case(string: str) -> str:
    """Convert PascalCaseString to a snake_case_string."""
    return _snake_2(_snake_1(string)).casefold()


class SQLModel(_SQLModel):
    @declared_attr
    def __tablename__(cls) -> str:
        """Return the snake_case version of the class name as the table name."""
        return snake_case(cls.__name__)