python · graingert · Jan 15, 2025 · Jan 15, 2025 · Jan 15, 2025 · Jan 15, 2025
diff --git a/Lib/doctest.py b/Lib/doctest.py
@@ -94,6 +94,7 @@ def _test():
 
 import __future__
 import difflib
+import importlib.resources
 import inspect
 import linecache
 import os
@@ -102,8 +103,8 @@ def _test():
 import sys
 import traceback
 import unittest
-from io import StringIO, IncrementalNewlineDecoder
 from collections import namedtuple
+from io import StringIO
 import _colorize  # Used in doctests
 from _colorize import ANSIColors, can_colorize
 
@@ -235,27 +236,21 @@ def _normalize_module(module, depth=2):
     else:
         raise TypeError("Expected a module, string, or None")
 
-def _newline_convert(data):
-    # The IO module provides a handy decoder for universal newline conversion
-    return IncrementalNewlineDecoder(None, True).decode(data, True)
-
 def _load_testfile(filename, package, module_relative, encoding):
+    text = None
     if module_relative:
-        package = _normalize_module(package, 3)
-        filename = _module_relative_path(package, filename)
-        if (loader := getattr(package, '__loader__', None)) is None:
-            try:
-                loader = package.__spec__.loader
-            except AttributeError:
-                pass
-        if hasattr(loader, 'get_data'):
-            file_contents = loader.get_data(filename)
-            file_contents = file_contents.decode(encoding)
-            # get_data() opens files as 'rb', so one must do the equivalent
-            # conversion as universal newlines would do.
-            return _newline_convert(file_contents), filename
-    with open(filename, encoding=encoding) as f:
-        return f.read(), filename
+        package = _normalize_module(package, depth=3)
+        try:
+            file = importlib.resources.files(package) / filename
+            text = file.read_text(encoding=encoding)
+        except AttributeError:
+            filename = _module_relative_path(package, filename)
+
+    if text is None:
+        with open(filename, encoding=encoding) as f:
+            text = f.read()
+
+    return text, filename
 
 def _indent(s, indent=4):
     """

diff --git a/Misc/NEWS.d/next/Library/2025-01-15-11-57-42.gh-issue-128862.TDHQdR.rst b/Misc/NEWS.d/next/Library/2025-01-15-11-57-42.gh-issue-128862.TDHQdR.rst
@@ -0,0 +1 @@
+Use ``importlib.resources`` to acquire test files in ``doctest``
-Use ``importlib.resources`` to acquire test files in ``doctest``
+Use :mod:`importlib.resources` to acquire test files in :mod:`doctest`.
-Use ``importlib.resources`` to acquire test files in ``doctest``
+Use :mod:`importlib.resources` to acquire test files in :mod:`doctest`.