Strict typing for IPython.utils.data and deprecate uniq_stable

Carreau · Carreau · commit b69d57334d44 · 2025-11-04T10:26:21.000+01:00
Note that implementation was wrong as see.add() is always None.
diff --git a/IPython/utils/data.py b/IPython/utils/data.py
@@ -9,22 +9,44 @@
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
+import warnings
+from collections.abc import Iterable, Sequence
+from typing import TypeVar
 
-def uniq_stable(elems):
+
+T = TypeVar("T")
+
+
+def uniq_stable(elems: Iterable[T]) -> list[T]:
     """uniq_stable(elems) -> list
 
+    .. deprecated:: 9.8
+        This function is deprecated and will be removed in a future version.
+        It is not used within IPython and was never part of the public API.
+
     Return from an iterable, a list of all the unique elements in the input,
     but maintaining the order in which they first appear.
 
     Note: All elements in the input must be hashable for this routine
     to work, as it internally uses a set for efficiency reasons.
     """
-    seen = set()
-    return [x for x in elems if x not in seen and not seen.add(x)]
-
-
-def chop(seq, size):
+    warnings.warn(
+        "uniq_stable is deprecated since IPython 9.8 and will be removed in a future version. "
+        "It was never part of the public API.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
+    seen: set[T] = set()
+    result: list[T] = []
+    for x in elems:
+        if x not in seen:
+            seen.add(x)
+            result.append(x)
+    return result
+
+
+def chop(seq: Sequence[T], size: int) -> list[Sequence[T]]:
     """Chop a sequence into chunks of the given size."""
-    return [seq[i:i+size] for i in range(0,len(seq),size)]
+    return [seq[i:i+size] for i in range(0, len(seq), size)]
 
 
