How does a minimal implementation of a Sequence from collections.abc, together with the correct type hints, look like? My current version is the following (with warnings from basedpyright): from collections.abc import Sequence from typing import override class MySeq(Sequence[float]): def __init__(self): self._data: list[float] = list() @override def __len__(self) -> int: return len(self._data) @override def __getitem__(self, key) -> float: # Type annotation is missing for parameter "key" return self._data[key] # Return type is unknown How do I type hint key? Just key: int is not accepted by the type checker. It gives the warning: "slice[Any, Any, Any]" is not assignable to "int". What choices do I have here? What is wrong with the return type? The full warning is "float" is not assignable to "Sequence[float]" Continue reading...
