bindings: python: make config iteration consistent

Previously, Chip.request_lines and LineRequest.reconfigure_lines
iterated over a config object but did so in subtly different ways.

Create a generator that iterates over a config object and returns line +
settings pairs. Update the aforementioned functions to use the generator
to consolidate and condense code.

Signed-off-by: Vincent Fazio <vfazio@gmail.com>
Link: https://lore.kernel.org/r/20251009130516.3729433-2-vfazio@gmail.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

bindings/python/gpiod/_internal.py

@@ -1,11 +1,18 @@
 # SPDX-License-Identifier: LGPL-2.1-or-later
 # SPDX-FileCopyrightText: 2022 Bartosz Golaszewski <brgl@bgdev.pl>
 
+from __future__ import annotations
+
 from datetime import timedelta
 from select import select
-from typing import Optional, Union
+from typing import TYPE_CHECKING, Optional, Union
 
-__all__ = ["poll_fd"]
+if TYPE_CHECKING:
+    from collections.abc import Generator, Iterable
+
+    from .line_settings import LineSettings
+
+__all__ = ["poll_fd", "config_iter"]
 
 
 def poll_fd(fd: int, timeout: Optional[Union[timedelta, float]] = None) -> bool:
@@ -17,3 +24,14 @@ def poll_fd(fd: int, timeout: Optional[Union[timedelta, float]] = None) -> bool:
 
     readable, _, _ = select([fd], [], [], sec)
     return True if fd in readable else False
+
+
+def config_iter(
+    config: dict[Union[Iterable[Union[int, str]], int, str], Optional[LineSettings]],
+) -> Generator[tuple[Union[int, str], Optional[LineSettings]]]:
+    for key, settings in config.items():
+        if isinstance(key, int) or isinstance(key, str):
+            yield key, settings
+        else:
+            for subkey in key:
+                yield subkey, settings

bindings/python/gpiod/chip.py

@@ -8,7 +8,7 @@ from errno import ENOENT
 from typing import TYPE_CHECKING, Optional, Union, cast
 
 from . import _ext
-from ._internal import poll_fd
+from ._internal import config_iter, poll_fd
 from .exception import ChipClosedError
 from .line import Value
 from .line_request import LineRequest
@@ -305,28 +305,24 @@ class Chip:
         offset_map = dict()
         global_output_values = list()
 
-        for lines, settings in config.items():
+        for line, settings in config_iter(config):
             offsets = list()
 
-            if isinstance(lines, int) or isinstance(lines, str):
-                lines = (lines,)
+            offset = self.line_offset_from_id(line)
+            offsets.append(offset)
 
-            for line in lines:
-                offset = self.line_offset_from_id(line)
-                offsets.append(offset)
+            # If there's a global output value for this offset, store it in the
+            # list for later.
+            if mapped_output_values:
+                global_output_values.append(
+                    mapped_output_values[offset]
+                    if offset in mapped_output_values
+                    else Value.INACTIVE
+                )
 
-                # If there's a global output value for this offset, store it in the
-                # list for later.
-                if mapped_output_values:
-                    global_output_values.append(
-                        mapped_output_values[offset]
-                        if offset in mapped_output_values
-                        else Value.INACTIVE
-                    )
-
-                if isinstance(line, str):
-                    name_map[line] = offset
-                    offset_map[offset] = line
+            if isinstance(line, str):
+                name_map[line] = offset
+                offset_map[offset] = line
 
             line_cfg.add_line_settings(
                 offsets, _line_settings_to_ext(settings or LineSettings())

bindings/python/gpiod/line_request.py

@@ -6,7 +6,7 @@ from __future__ import annotations
 from typing import TYPE_CHECKING, Optional, Union, cast
 
 from . import _ext
-from ._internal import poll_fd
+from ._internal import config_iter, poll_fd
 from .exception import RequestReleasedError
 from .line_settings import LineSettings, _line_settings_to_ext
 
@@ -174,13 +174,9 @@ class LineRequest:
         line_cfg = _ext.LineConfig()
         line_settings = {}
 
-        for lines, settings in config.items():
-            if isinstance(lines, int) or isinstance(lines, str):
-                lines = [lines]
-
-            for line in lines:
-                offset = self._line_to_offset(line)
-                line_settings[offset] = settings
+        for line, settings in config_iter(config):
+            offset = self._line_to_offset(line)
+            line_settings[offset] = settings
 
         for offset in self.offsets:
             settings = line_settings.get(offset) or LineSettings()