Final QA (#451)

python-type-hints-multiple-types/01_type_hints_for_one_piece_of_data.py

@@ -5,7 +5,10 @@ def parse_email(email_address: str) -> str | None:
     return None
 
 
+# %% Python 3.9 and earlier
+
 # from typing import Union
+#
 # def parse_email(email_address: str) -> Union[str, None]:
 #     if "@" in email_address:
 #         username, domain = email_address.split("@")

python-type-hints-multiple-types/02_type_hints_for_multiple_pieces_of_data.py

@@ -5,7 +5,10 @@ def parse_email(email_address: str) -> tuple[str, str] | None:
     return None
 
 
+# %% Python 3.9 and earlier
+
 # from typing import Tuple, Union
+#
 # def parse_email(email_address: str) -> Union[Tuple[str, str], None]:
 #     if "@" in email_address:
 #         username, domain = email_address.split("@")

python-type-hints-multiple-types/03_type_hints_for_callback.py

@@ -1,16 +1,19 @@
 from collections.abc import Callable
-from typing import Any
+from typing import ParamSpec, TypeVar
 
+P = ParamSpec("P")
+T = TypeVar("T")
 
-def apply_func(func: Callable[..., Any], *args: Any) -> Any:
-    return func(*args)
 
+def apply_func(func: Callable[P, T], *args: P.args, **kwargs: P.kwargs) -> T:
+    return func(*args, **kwargs)
 
-def parse_email(email_address: str) -> tuple[str, str] | None:
+
+def parse_email(email_address: str) -> tuple[str, str]:
     if "@" in email_address:
         username, domain = email_address.split("@")
         return username, domain
-    return None
+    return "", ""
 
 
 apply_func(parse_email, "[email protected]")

python-type-hints-multiple-types/04_type_hints_for_factory_function.py

@@ -1,12 +1,15 @@
 import functools
 import time
 from collections.abc import Callable
-from typing import Any
+from typing import ParamSpec, TypeVar
 
+P = ParamSpec("P")
+T = TypeVar("T")
 
-def timeit(function: Callable[..., Any]) -> Callable[..., Any]:
+
+def timeit(function: Callable[P, T]) -> Callable[P, T]:
     @functools.wraps(function)
-    def wrapper(*args, **kwargs):
+    def wrapper(*args: P.args, **kwargs: P.kwargs):
         start = time.perf_counter()
         result = function(*args, **kwargs)
         end = time.perf_counter()
@@ -17,11 +20,11 @@ def wrapper(*args, **kwargs):
 
 
 @timeit
-def parse_email(email_address: str) -> tuple[str, str] | None:
+def parse_email(email_address: str) -> tuple[str, str]:
     if "@" in email_address:
         username, domain = email_address.split("@")
         return username, domain
-    return None
+    return "", ""
 
 
 username, domain = parse_email("[email protected]")

python-type-hints-multiple-types/05_type_hints_for_generator.py

@@ -8,7 +8,7 @@ def parse_email() -> Generator[tuple[str, str], str, str]:
             username, domain = sent.split("@")
             sent = yield username, domain
         else:
-            sent = yield "invalid email"
+            sent = yield "ERROR", "invalid email"
     return "Done"