Use forward type annotations

Besides improving code legibility, they are necessary for the rendered
documentation to be properly cross-referenced (otherwise the types
appear just as a string, without links).

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

examples/sdk_usage_example.py

@@ -8,6 +8,8 @@
 Second user receives requests and set that power.
 """
 
+from __future__ import annotations
+
 import asyncio
 import logging
 from datetime import datetime, timezone
@@ -136,7 +138,7 @@ async def run(self) -> None:
             RuntimeError: If communication channel has been closed.
         """
         while True:
-            queue: "Queue[Optional[float]]" = Queue(maxsize=50)
+            queue: Queue[Optional[float]] = Queue(maxsize=50)
             for _ in range(5):
                 active_power = await self._active_power_data.receive()
                 if active_power is None:

src/frequenz/sdk/data_handling/power.py

@@ -3,6 +3,8 @@
 
 """Provides support for processing power measurements from different microgrid components."""
 
+from __future__ import annotations
+
 from numbers import Real
 
 from frequenz.api.microgrid.common_pb2 import AC
@@ -36,7 +38,7 @@ def __init__(self, complex_power: complex) -> None:
         self._complex_power = complex_power
 
     @classmethod
-    def from_protobuf(cls, ac_message: AC) -> "ComplexPower":
+    def from_protobuf(cls, ac_message: AC) -> ComplexPower:
         """Create a ComplexPower value from the AC type of the microgrid gRPC API.
 
         Args:
@@ -54,7 +56,7 @@ def from_protobuf(cls, ac_message: AC) -> "ComplexPower":
         return cls(complex(active, reactive))
 
     @classmethod
-    def from_active_power(cls, active_power: float) -> "ComplexPower":
+    def from_active_power(cls, active_power: float) -> ComplexPower:
         """Create a ComplexPower value from a numerical active power value.
 
         Args:
@@ -68,7 +70,7 @@ def from_active_power(cls, active_power: float) -> "ComplexPower":
         return cls(complex(active_power, 0))
 
     @classmethod
-    def from_reactive_power(cls, reactive_power: float) -> "ComplexPower":
+    def from_reactive_power(cls, reactive_power: float) -> ComplexPower:
         """Create a ComplexPower value from a numerical reactive power value.
 
         Args:
@@ -161,15 +163,15 @@ def capacitive(self) -> float:
         """
         return max(-self.imag, 0)
 
-    def __neg__(self) -> "ComplexPower":
+    def __neg__(self) -> ComplexPower:
         """Generate the negative of this value.
 
         Returns:
             Value whose real and imaginary parts are the negative of this instance's
         """
         return ComplexPower(-self._complex_power)
 
-    def __add__(self, other: object) -> "ComplexPower":
+    def __add__(self, other: object) -> ComplexPower:
         """Add this complex power value to the provided `other`.
 
         Args:
@@ -183,7 +185,7 @@ def __add__(self, other: object) -> "ComplexPower":
 
         return ComplexPower(self._complex_power + other._complex_power)
 
-    def __sub__(self, other: object) -> "ComplexPower":
+    def __sub__(self, other: object) -> ComplexPower:
         """Subtract the provided `other` from this complex power value.
 
         Args:
@@ -197,7 +199,7 @@ def __sub__(self, other: object) -> "ComplexPower":
 
         return ComplexPower(self._complex_power - other._complex_power)
 
-    def __mul__(self, other: object) -> "ComplexPower":
+    def __mul__(self, other: object) -> ComplexPower:
         """Multiply this complex power value by the provided scalar.
 
         Args:
@@ -213,7 +215,7 @@ def __mul__(self, other: object) -> "ComplexPower":
 
     __rmul__ = __mul__
 
-    def __truediv__(self, other: object) -> "ComplexPower":
+    def __truediv__(self, other: object) -> ComplexPower:
         """Divide this complex power value by the provided scalar.
 
         Args:

src/frequenz/sdk/data_ingestion/microgrid_data.py

@@ -7,6 +7,9 @@
 Including default standard formulas for client load, grid load, total pv production,
 ev charging rate, battery SoC, active power, max consume and supply rate.
 """
+
+from __future__ import annotations
+
 import asyncio
 import logging
 from datetime import datetime, timezone
@@ -93,7 +96,7 @@ async def resend_formulas(self) -> None:
         """Send formulas results with some period."""
         # Sleep first to collect initial data from all component
         await asyncio.sleep(self._wait_for_data_sec)
-        tasks: List["asyncio.Task[bool]"] = []
+        tasks: List[asyncio.Task[bool]] = []
         while True:
             start_time = datetime.now(timezone.utc)
             # For every formula that was updated at least once, send that formula.
@@ -175,7 +178,7 @@ def parse_formula_overrides(self, config: Config) -> Dict[str, Set[int]]:
 
     # pylint: disable=unused-argument
     async def _reinitialize(
-        self, config: Config, resend_formulas_task: "asyncio.Task[None]"
+        self, config: Config, resend_formulas_task: asyncio.Task[None]
     ) -> None:
         """Reinitialize MicrogridData with updated config.
 

src/frequenz/sdk/microgrid/component.py

@@ -3,6 +3,8 @@
 
 """Defines the components that can be used in a microgrid."""
 
+from __future__ import annotations
+
 from dataclasses import dataclass
 from enum import Enum
 
@@ -28,7 +30,7 @@ class ComponentCategory(Enum):
 
 
 def _component_category_from_protobuf(
-    component_category: "microgrid_pb.ComponentCategory.ValueType",
+    component_category: microgrid_pb.ComponentCategory.ValueType,
 ) -> ComponentCategory:
     """Convert a protobuf ComponentCategory message to ComponentCategory enum.
 

src/frequenz/sdk/microgrid/retry.py

@@ -3,6 +3,8 @@
 
 """Implementations for retry strategies."""
 
+from __future__ import annotations
+
 import random
 from abc import ABC, abstractmethod
 from copy import deepcopy
@@ -47,7 +49,7 @@ def reset(self) -> None:
         """
         self._count = 0
 
-    def copy(self) -> "RetryStrategy":
+    def copy(self) -> RetryStrategy:
         """Create a new instance of `self`.
 
         Returns:

src/frequenz/sdk/power_distribution/power_distributor.py

@@ -5,6 +5,9 @@
 
 Purpose of this tool is to keep SoC level of each component at the equal level.
 """
+
+from __future__ import annotations
+
 import asyncio
 import logging
 from asyncio.tasks import ALL_COMPLETED
@@ -153,7 +156,7 @@ def __init__(
         # important. It will execute both. And later request will override the previous
         # one.
         # That is why the queue of maxsize = total number of batteries should be enough.
-        self._request_queue: "asyncio.Queue[Tuple[Request, User]]" = asyncio.Queue(
+        self._request_queue: asyncio.Queue[Tuple[Request, User]] = asyncio.Queue(
             maxsize=len(self._bat_inv_map)
         )
 
@@ -315,7 +318,7 @@ def _check_request(self, request: Request) -> Optional[Result]:
 
     def _remove_duplicated_requests(
         self, request: Request, user: User
-    ) -> List["asyncio.Task[bool]"]:
+    ) -> List[asyncio.Task[bool]]:
         """Remove duplicated requests from the queue.
 
         Remove old requests in which set of batteries are the same as in new request.
@@ -332,7 +335,7 @@ def _remove_duplicated_requests(
         batteries = request.batteries
 
         good_requests: List[Tuple[Request, User]] = []
-        to_ignore: List["asyncio.Task[bool]"] = []
+        to_ignore: List[asyncio.Task[bool]] = []
 
         while not self._request_queue.empty():
             prev_request, prev_user = self._request_queue.get_nowait()
@@ -606,7 +609,7 @@ def _parse_result(
 
         return any_fail, failed_power
 
-    async def _cancel_tasks(self, tasks: Iterable["asyncio.Task[Any]"]) -> None:
+    async def _cancel_tasks(self, tasks: Iterable[asyncio.Task[Any]]) -> None:
         """Cancel given asyncio tasks and wait for them.
 
         Args:

tests/test_microgrid/mock_api.py

@@ -8,6 +8,7 @@
 all framework code, as API integration should be highly encapsulated.
 """
 
+from __future__ import annotations
 
 # pylint: disable=invalid-name,no-name-in-module,unused-import
 from concurrent import futures
@@ -59,7 +60,7 @@ class MockMicrogridServicer(  # pylint: disable=too-many-public-methods
 
     def __init__(
         self,
-        components: Optional[List[Tuple[int, "ComponentCategory.V"]]] = None,
+        components: Optional[List[Tuple[int, ComponentCategory.V]]] = None,
         connections: Optional[List[Tuple[int, int]]] = None,
     ) -> None:
         """Create a MockMicrogridServicer instance."""
@@ -76,7 +77,7 @@ def __init__(
         self._latest_discharge: Optional[PowerLevelParam] = None
 
     def add_component(
-        self, component_id: int, component_category: "ComponentCategory.V"
+        self, component_id: int, component_category: ComponentCategory.V
     ) -> None:
         """Add a component to the mock service."""
         self._components.append(Component(id=component_id, category=component_category))
@@ -85,9 +86,7 @@ def add_connection(self, start: int, end: int) -> None:
         """Add a connection to the mock service."""
         self._connections.append(Connection(start=start, end=end))
 
-    def set_components(
-        self, components: List[Tuple[int, "ComponentCategory.V"]]
-    ) -> None:
+    def set_components(self, components: List[Tuple[int, ComponentCategory.V]]) -> None:
         """Set components to mock service, dropping existing."""
         self._components.clear()
         self._components.extend(