use __futures__.annotations

Author: tekktrik

adafruit_ble/__init__.py

@@ -9,7 +9,11 @@
 building on the native `_bleio` module.
 
 """
+
+from __future__ import annotations
+
 # pylint: disable=wrong-import-position
+
 import sys
 
 if sys.implementation.name == "circuitpython" and sys.implementation.version[0] <= 4:
@@ -24,10 +28,14 @@
 from .advertising import Advertisement
 
 try:
-    from typing import Optional, Iterator, Union, Tuple, Literal, NoReturn
-    from circuitpython_typing import ReadableBuffer
-    from adafruit_ble.uuid import UUID
-    from adafruit_ble.characteristics import Characteristic
+    from typing import Optional, Iterator, Union, Tuple, NoReturn, TYPE_CHECKING
+    from typing_extensions import Literal
+
+    if TYPE_CHECKING:
+        from circuitpython_typing import ReadableBuffer
+        from adafruit_ble.uuid import UUID
+        from adafruit_ble.characteristics import Characteristic
+
 except ImportError:
     pass
 
@@ -220,7 +228,7 @@ def start_scan(
         interval: float = 0.1,
         window: float = 0.1,
         minimum_rssi: int = -80,
-        active: bool = True
+        active: bool = True,
     ) -> Iterator[Advertisement]:
         """
         Starts scanning. Returns an iterator of advertisement objects of the types given in

adafruit_ble/advertising/__init__.py

@@ -6,13 +6,18 @@
 Advertising is the first phase of BLE where devices can broadcast
 """
 
+from __future__ import annotations
+
 import struct
 
 try:
-    from typing import Dict, Any, Union, List, Optional, Type, Literal, TypeVar
-    from _bleio import ScanEntry
+    from typing import Dict, Any, Union, List, Optional, Type, TypeVar, TYPE_CHECKING
+    from typing_extensions import Literal
+
+    if TYPE_CHECKING:
+        from _bleio import ScanEntry
 
-    LazyObjectField_GivenClass = TypeVar("LazyObjectField_GivenClass")
+        LazyObjectField_GivenClass = TypeVar("LazyObjectField_GivenClass")
 
 except ImportError:
     pass

adafruit_ble/characteristics/__init__.py

@@ -8,16 +8,21 @@
 
 """
 
+from __future__ import annotations
+
 import struct
 import _bleio
 
 from ..attributes import Attribute
 
 try:
-    from typing import Optional, Type, Union, Tuple, Iterable
-    from circuitpython_typing import ReadableBuffer
-    from adafruit_ble.uuid import UUID
-    from adafruit_ble.services import Service
+    from typing import Optional, Type, Union, Tuple, Iterable, TYPE_CHECKING
+
+    if TYPE_CHECKING:
+        from circuitpython_typing import ReadableBuffer
+        from adafruit_ble.uuid import UUID
+        from adafruit_ble.services import Service
+
 except ImportError:
     pass
 
@@ -89,7 +94,7 @@ def __init__(
         write_perm: int = Attribute.OPEN,
         max_length: Optional[int] = None,
         fixed_length: bool = False,
-        initial_value: Optional[ReadableBuffer] = None
+        initial_value: Optional[ReadableBuffer] = None,
     ) -> None:
         self.field_name = None  # Set by Service during basic binding
 
@@ -179,7 +184,7 @@ def __init__(
         write_perm: int = Attribute.OPEN,
         max_length: int = 20,
         fixed_length: bool = False,
-        initial_value: Optional[ReadableBuffer] = None
+        initial_value: Optional[ReadableBuffer] = None,
     ) -> None:
         self.field_name = None  # Set by Service during basic binding
 
@@ -240,7 +245,7 @@ def __init__(
         properties: int = 0,
         read_perm: int = Attribute.OPEN,
         write_perm: int = Attribute.OPEN,
-        initial_value: Optional[ReadableBuffer] = None
+        initial_value: Optional[ReadableBuffer] = None,
     ) -> None:
         self._struct_format = struct_format
         self._expected_size = struct.calcsize(struct_format)