| name | python-scala-oop |
| description | Translating Python classes, inheritance, and generic variance to Scala equivalents. |
Python to Scala OOP and Generics
This skill covers the translation of object-oriented concepts from Python to Scala.
Classes and Inheritance
Data Classes
- Python:
@dataclass(frozen=True)
- Scala:
case class (immutable by default, comes with copy and structural equality).
Abstract Base Classes
- Python:
ABC and @abstractmethod
- Scala:
abstract class or trait. Use trait when multiple inheritance is needed.
Methods
- Python:
def my_method(self, arg):
- Scala:
def myMethod(arg: Type): ReturnType = { ... }
Enums
- Python:
class Color(Enum):
- Scala:
object Color extends Enumeration { val Red, Green, Blue = Value } or (better) sealed trait Color.
Generics and Variance
| Python | Scala | Notes |
|---|
Generic[T] | [T] | Invariant |
Generic[T_co] | [+T] | Covariant (can return subtypes) |
Generic[T_contra] | [-T] | Contravariant (can accept supertypes) |
Covariance (+T)
Useful for read-only containers (e.g., List[+A]).
class Container[+T](val item: T)
Contravariance (-T)
Useful for consumers or sinks.
trait Sink[-T] { def consume(item: T): Unit }
Structural Typing (Protocols)
- Python:
@runtime_checkable class Protocol:
- Scala:
trait or structural types type MyType = { def method(): Unit }. Usually, explicit traits are preferred.
