Drop use of non-standard pkg_resources API

isort/settings.py

@@ -46,6 +46,11 @@
 from .wrap_modes import from_string as wrap_mode_from_string
 
 if TYPE_CHECKING:
+    if sys.version_info < (3, 10):  # pragma: no cover
+        EntryPoints = Any
+    else:
+        from importlib.metadata import EntryPoints
+
     tomllib: Any
 else:
     if sys.version_info >= (3, 11):
@@ -356,9 +361,7 @@ def __init__(
         profile: Dict[str, Any] = {}
         if profile_name:
             if profile_name not in profiles:
-                import pkg_resources
-
-                for plugin in pkg_resources.iter_entry_points("isort.profiles"):
+                for plugin in entry_points(group="isort.profiles"):
                     profiles.setdefault(plugin.name, plugin.load())
 
             if profile_name not in profiles:
@@ -473,9 +476,7 @@ def __init__(
             combined_config["src_paths"] = tuple(src_paths)
 
         if "formatter" in combined_config:
-            import pkg_resources
-
-            for plugin in pkg_resources.iter_entry_points("isort.formatters"):
+            for plugin in entry_points(group="isort.formatters"):
                 if plugin.name == combined_config["formatter"]:
                     combined_config["formatting_function"] = plugin.load()
                     break
@@ -715,9 +716,7 @@ def sorting_function(self) -> Callable[..., List[str]]:
             self._sorting_function = sorted
         else:
             available_sort_orders = ["natural", "native"]
-            import pkg_resources
-
-            for sort_plugin in pkg_resources.iter_entry_points("isort.sort_function"):
+            for sort_plugin in entry_points(group="isort.sort_function"):
                 available_sort_orders.append(sort_plugin.name)
                 if sort_plugin.name == self.sort_order:
                     self._sorting_function = sort_plugin.load()
@@ -938,4 +937,17 @@ def _as_bool(value: str) -> bool:
         raise ValueError(f"invalid truth value {value}")
 
 
+def entry_points(group: str) -> "EntryPoints":
+    """Call entry_point after lazy loading it.
+
+    TODO: The reason for lazy loading here are unknown.
+    """
+    if sys.version_info < (3, 10):  # pragma: no cover
+        from importlib_metadata import entry_points
+    else:
+        from importlib.metadata import entry_points
+
+    return entry_points(group=group)
+
+
 DEFAULT_CONFIG = Config()

pyproject.toml

@@ -38,7 +38,13 @@ include = [
 ]
 requires-python = ">=3.9.0"
 
-dependencies = []
+dependencies = [
+    # we only need the entry_points() function, which appeared in the stdlib
+    # in Python 3.10.
+    # importlib_metadata 4.6 is the version matching stdlib 3.10
+    # See grid at https://pypi.org/project/importlib-metadata/
+    "importlib_metadata >= 4.6.0; python_version < '3.10'",
+]
 
 [project.urls]
 Homepage = "https://pycqa.github.io/isort/index.html"
@@ -174,6 +180,10 @@ allow_untyped_defs = true
 allow_incomplete_defs = true
 allow_untyped_calls = true
 
+[[tool.mypy.overrides]]
+module = "importlib_metadata.*"
+ignore_missing_imports = true
+
 [tool.ruff]
 line-length = 100
 lint.select = [

tests/unit/test_regressions.py

@@ -1875,11 +1875,7 @@ class Bar:
 def test_isort_should_produce_the_same_code_on_subsequent_runs_issue_1799(tmpdir):
     code = """import sys
 
-if sys.version_info[:2] >= (3, 8):
-    # TODO: Import directly (no need for conditional) when `python_requires = >= 3.8`
-    from importlib.metadata import PackageNotFoundError, version  # pragma: no cover
-else:
-    from importlib_metadata import PackageNotFoundError, version  # pragma: no cover
+from importlib.metadata import PackageNotFoundError, version
 """
     config_file = tmpdir.join(".isort.cfg")
     config_file.write(