1 files changed, 31 insertions, 11 deletions
diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
index c74c3a31909..48e74adcce3 100644
--- a/Lib/test/support/__init__.py
+++ b/Lib/test/support/__init__.py
@@ -696,9 +696,11 @@ def sortdict(dict):
     return "{%s}" % withcommas
 
 
-def run_code(code: str) -> dict[str, object]:
+def run_code(code: str, extra_names: dict[str, object] | None = None) -> dict[str, object]:
     """Run a piece of code after dedenting it, and return its global namespace."""
     ns = {}
+    if extra_names:
+        ns.update(extra_names)
     exec(textwrap.dedent(code), ns)
     return ns
 
@@ -943,6 +945,31 @@ def check_sizeof(test, o, size):
             % (type(o), result, size)
     test.assertEqual(result, size, msg)
 
+def subTests(arg_names, arg_values, /, *, _do_cleanups=False):
+    """Run multiple subtests with different parameters.
+    """
+    single_param = False
+    if isinstance(arg_names, str):
+        arg_names = arg_names.replace(',',' ').split()
+        if len(arg_names) == 1:
+            single_param = True
+    arg_values = tuple(arg_values)
+    def decorator(func):
+        if isinstance(func, type):
+            raise TypeError('subTests() can only decorate methods, not classes')
+        @functools.wraps(func)
+        def wrapper(self, /, *args, **kwargs):
+            for values in arg_values:
+                if single_param:
+                    values = (values,)
+                subtest_kwargs = dict(zip(arg_names, values))
+                with self.subTest(**subtest_kwargs):
+                    func(self, *args, **kwargs, **subtest_kwargs)
+                if _do_cleanups:
+                    self.doCleanups()
+        return wrapper
+    return decorator
+
 #=======================================================================
 # Decorator/context manager for running a code in a different locale,
 # correctly resetting it afterwards.
@@ -1082,7 +1109,7 @@ def set_memlimit(limit: str) -> None:
     global real_max_memuse
     memlimit = _parse_memlimit(limit)
     if memlimit < _2G - 1:
-        raise ValueError('Memory limit {limit!r} too low to be useful')
+        raise ValueError(f'Memory limit {limit!r} too low to be useful')
 
     real_max_memuse = memlimit
     memlimit = min(memlimit, MAX_Py_ssize_t)
@@ -1099,7 +1126,6 @@ class _MemoryWatchdog:
         self.started = False
 
     def start(self):
-        import warnings
         try:
             f = open(self.procfile, 'r')
         except OSError as e:
@@ -2357,7 +2383,7 @@ def infinite_recursion(max_depth=None):
         # very deep recursion.
         max_depth = 20_000
     elif max_depth < 3:
-        raise ValueError("max_depth must be at least 3, got {max_depth}")
+        raise ValueError(f"max_depth must be at least 3, got {max_depth}")
     depth = get_recursion_depth()
     depth = max(depth - 1, 1)  # Ignore infinite_recursion() frame.
     limit = depth + max_depth
@@ -2726,7 +2752,7 @@ def iter_builtin_types():
     # Fall back to making a best-effort guess.
     if hasattr(object, '__flags__'):
         # Look for any type object with the Py_TPFLAGS_STATIC_BUILTIN flag set.
-        import datetime
+        import datetime  # noqa: F401
         seen = set()
         for cls, subs in walk_class_hierarchy(object):
             if cls in seen:
@@ -2927,12 +2953,6 @@ def make_clean_env() -> dict[str, str]:
     return clean_env
 
 
-def initialized_with_pyrepl():
-    """Detect whether PyREPL was used during Python initialization."""
-    # If the main module has a __file__ attribute it's a Python module, which means PyREPL.
-    return hasattr(sys.modules["__main__"], "__file__")
-
-
 WINDOWS_STATUS = {
     0xC0000005: "STATUS_ACCESS_VIOLATION",
     0xC00000FD: "STATUS_STACK_OVERFLOW",