Merge pull request #110 from isaacharrisholt/typing-fixes

fix: correct typing for basemodel return types

Author: isaacharrisholt

quiffen/core/base.py

@@ -1,10 +1,8 @@
 from abc import abstractmethod
-from typing import Any, Dict, Generic, Iterable, List, Optional, Type, TypeVar
+from typing import Any, Dict, Iterable, List, Optional, Type, TypeVar
 
 from pydantic import BaseModel as PydanticBaseModel
 
-T = TypeVar("T")
-
 
 class Field(PydanticBaseModel):
     """A custom field for a QIF object.
@@ -38,7 +36,10 @@ def __lt__(self, other) -> bool:
         )
 
 
-class BaseModel(PydanticBaseModel, Generic[T]):
+TModel = TypeVar("TModel", bound="BaseModel")
+
+
+class BaseModel(PydanticBaseModel):
     class Config:
         extra = "allow"
 
@@ -85,11 +86,11 @@ def _get_custom_fields(cls) -> List[Field]:
 
     @classmethod
     @abstractmethod
-    def from_list(cls, lst: List[str]) -> T:
+    def from_list(cls: Type[TModel], lst: List[str]) -> TModel:
         pass
 
     @classmethod
-    def from_string(cls, string: str, separator: str = "\n") -> T:
+    def from_string(cls: Type[TModel], string: str, separator: str = "\n") -> TModel:
         """Create a class instance from a string."""
         return cls.from_list(string.split(separator))
 

quiffen/core/transaction.py

@@ -319,7 +319,7 @@ def to_qif(
         return qif
 
     @classmethod
-    def from_list(
+    def from_list(  # type: ignore - this one needs an incompatible return type
         cls,
         lst: List[str],
         day_first: bool = False,