[Python] How to avoid a NameError in SQLAlchemy when using an ORM for a MySQL database?

How do I avoid having a NameError when the class definitions for each table is in a different file when using SQLAlchemy to manage a MySQL database?

For example:

# in dish.py

class Dish(Base):
__tablename__ = "dishes"
ID: Mapped[int] = mapped_column(Integer, primary_key=True)
name: Mapped[str] = mapped_column(String(255))

composition: Mapped[List["Recipe"]] = relationship(
back_populates="dish",
foreign_keys="Recipe.ID_dish")

def get_ingredient_list(self):
return composition

# in ingredient.py

class Ingredient(Base):
__tablename__ = "ingredients"
ID: Mapped[int] = mapped_column(Integer, primary_key=True)
name: Mapped[str] = mapped_column(String(255))

in_dishes: Mapped[List["Recipe"]] = relationship(
back_populates="ingredient",
foreign_keys="Recipe.ID_ingredient")

# in recipe.py (the linking table)

class Recipe(Base):
__tablename__ = "recipe"
ID_dish: Mapped[int] = mapped_column(Integer, ForeignKey("dishes.ID"), primary_key=True)
ID_ingredient: Mapped[int] = mapped_column(Integer, ForeignKey("ingredients.ID"), primary_key=True)
amount: Mapped[float] = mapped_column(DECIMAL(5,2))

dish: Mapped["Dish"] = relationship(
back_populates="composition",
foreign_keys=[ID_dish])

ingredient: Mapped["Ingredient"] = relationship(
back_populates="in_dishes",
foreign_keys=[ID_ingredient])

# in the main file

from dish import Dish
from ingredient import Ingredient
from recipe import Recipe

ing_list = some_dish.get_ingredient_list()
print(ing_list)



My problem is that this returns a NameError where the classes are not defined. I guess this happens because the related classes are not imported in the modules.

How can I solve this problem?

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