feat!: drop Python 3.9 support (#1328)

* feat!: drop support for Python 3.9

* refactor: remove obsolete stdlib behaviour

* refactor: remove obsolete script to generate stdlibs

* test: require Python `>=3.10`

Author: mkniewallner

.github/workflows/main.yml

@@ -70,7 +70,6 @@ jobs:
           - name: windows
             image: windows-2025
         python-version:
-          - '3.9'
           - '3.10'
           - '3.11'
           - '3.12'

pyproject.toml

@@ -4,7 +4,7 @@ version = "0.0.1"
 description = "A command line utility to check for unused, missing and transitive dependencies in a Python project."
 authors = [{ name = "Florian Maas", email = "[email protected]" }]
 maintainers = [{ name = "Mathieu Kniewallner", email = "[email protected]" }]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 license = { file = "LICENSE" }
 readme = "README.md"
 classifiers = [
@@ -14,7 +14,6 @@ classifiers = [
     "Topic :: Software Development :: Libraries :: Python Modules",
     "Topic :: Software Development :: Quality Assurance",
     "Programming Language :: Python",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
@@ -103,7 +102,7 @@ source = ["python/deptry"]
 
 [tool.mypy]
 mypy_path = "python"
-files = ["python/deptry", "scripts", "tests"]
+files = ["python/deptry", "tests"]
 explicit_package_bases = true
 exclude = ["tests/fixtures"]
 disallow_any_unimported = true
@@ -123,11 +122,7 @@ module = ["xdist.*"]
 ignore_missing_imports = true
 
 [tool.deptry]
-extend_exclude = [
-    "docs",
-    "tests",
-    "scripts",
-]
+extend_exclude = ["docs", "tests"]
 
 [tool.deptry.per_rule_ignores]
 DEP001 = ["tomllib"]

python/deptry/core.py

@@ -7,12 +7,10 @@
 from typing import TYPE_CHECKING
 
 from deptry.dependency_getter.builder import DependencyGetterBuilder
-from deptry.exceptions import UnsupportedPythonVersionError
 from deptry.imports.extract import get_imported_modules_from_list_of_files
 from deptry.module import ModuleBuilder, ModuleLocations
 from deptry.python_file_finder import get_all_python_files_in
 from deptry.reporters import JSONReporter, TextReporter
-from deptry.stdlibs import STDLIBS_PYTHON
 from deptry.violations.finder import find_violations
 
 if TYPE_CHECKING:
@@ -139,13 +137,7 @@ def _directory_has_python_files(self, path: Path) -> bool:
 
     @staticmethod
     def _get_standard_library_modules() -> frozenset[str]:
-        if sys.version_info[:2] >= (3, 10):
-            return sys.stdlib_module_names
-
-        try:  # type: ignore[unreachable, unused-ignore]
-            return STDLIBS_PYTHON[f"{sys.version_info[0]}{sys.version_info[1]}"]
-        except KeyError as e:
-            raise UnsupportedPythonVersionError((sys.version_info[0], sys.version_info[1])) from e
+        return sys.stdlib_module_names
 
     def _log_config(self) -> None:
         logging.debug("Running with the following configuration:")

python/deptry/exceptions.py

@@ -21,13 +21,6 @@ def __init__(self, directory: Path) -> None:
         super().__init__(f"No file `pyproject.toml` found in directory {directory}")
 
 
-class UnsupportedPythonVersionError(ValueError):
-    def __init__(self, version: tuple[int, int]) -> None:
-        super().__init__(
-            f"Python version {version[0]}.{version[1]} is not supported. Only versions >= 3.9 are supported."
-        )
-
-
 class InvalidPyprojectTOMLOptionsError(UsageError):
     def __init__(self, invalid_options: list[str]) -> None:
         super().__init__(