fix(models): rename list()'s type= param to mtype=, matching stale docs

src/roboticstoolbox/models/list.py

@@ -8,21 +8,21 @@
 # import importlib
 
 
-def list(keywords=None, dof=None, type=None, border="thin"):
+def list(keywords=None, dof=None, mtype=None, border="thin"):
     """
     Display all robot models in summary form
 
     :param keywords: keywords to filter on, defaults to None
     :type keywords: tuple of str, optional
     :param dof: number of DoF to filter on, defaults to None
     :type dof: int, optional
-    :param type: model type "DH", "ETS", "URDF", defaults to all types
-    :type type: str, optional
+    :param mtype: model type "DH", "ETS", "URDF", defaults to all types
+    :type mtype: str, optional
 
     - ``list()`` displays a list of all models provided by the Toolbox.  It
       lists the name, manufacturer, model type, number of DoF, and keywords.
 
-    - ``list(type=MT)`` as above, but only displays models of type ``MT``
+    - ``list(mtype=MT)`` as above, but only displays models of type ``MT``
       where ``MT`` is one of "DH", "ETS" or "URDF".
 
     - ``list(keywords=KW)`` as above, but only displays models that have a
@@ -61,8 +61,8 @@ def make_table(border=None):
             border=border,
         )
 
-        if type is not None:
-            categories = [type]
+        if mtype is not None:
+            categories = [mtype]
         else:
             categories = ["DH", "URDF", "ETS"]
         for category in categories:

tech-debt.md

@@ -683,3 +683,36 @@ handles the shadowing correctly on its own. Also worth a quick sweep for
 any other `sys.version_info`/Python-3.10-specific conditionals elsewhere in
 the codebase at that point, so 3.10 cleanup happens in one pass rather than
 piecemeal.
+
+## `roboticstoolbox.models.list()` shadows the builtin `list`
+
+### Background
+
+Found 2026-07-05 while fixing a stale `mtype=` kwarg in the docs
+(`arm_dh.rst`/`arm_erobot.rst` runblock examples called
+`rtb.models.list(mtype="DH")`, but the function's parameter had been
+renamed to `type` at some point without updating the docs).
+
+Two things stood out while looking at `src/roboticstoolbox/models/list.py`:
+
+1. The function itself is named `list`, shadowing the builtin `list`
+   within any scope that does `from roboticstoolbox.models.list import
+   list` or `import roboticstoolbox.models as models; models.list(...)`.
+   It's always called qualified (`rtb.models.list(...)`) in practice, so
+   this hasn't bitten anyone yet, but it's a landmine for future edits to
+   that file — reaching for `list(...)` to build an actual list inside the
+   function body would silently recurse/shadow instead of erroring.
+2. (Already fixed, see commit around 2026-07-05) one of its parameters was
+   named `type`, shadowing the builtin `type`. This has been renamed to
+   `mtype` — matching what the docs already (mistakenly, but presciently)
+   assumed the parameter was called — and all call sites (docs, tests)
+   updated to match.
+
+### Proposed fix
+
+Renaming the function itself (e.g. to `list_models`) would fix the
+remaining shadowing, but `list` is public API (`rtb.models.list`) and a
+rename is a breaking change for any external callers — deferred rather
+than done opportunistically. If/when a broader API-breaking pass happens
+on this module (or at the next major version bump), rename `list` to
+something that doesn't shadow a builtin.

tests/test_models.py

@@ -13,7 +13,7 @@ class TestModels(unittest.TestCase):
     def test_list(self):
         rp.models.list()
         rp.models.list("UR", 6)
-        rp.models.list(type="DH")
+        rp.models.list(mtype="DH")
 
     def test_puma(self):
         puma = rp.models.DH.Puma560()