0. emacs -Q, where Emacs has been built with treesitter support and the treesitter Python grammar library is installed. 1. Visit the attached file "test.py", which contains examples in Python of variables and function parameters with type hints. The buffer is now in the default (non-treesitter) python-mode. 2. Notice that the initialized annotated variable `age' and the (unannotated) assigned to occurrences of `child' are fontified with font-lock-variable-name-face, while the uninitialized annotated variables `a' and `child' and the annotated function parameters `num', `num1' and `num2' are displayed in the default face. 3. M-x python-ts-mode. Now the uninitialized `age', `a' and `child' as well as the function parameters `num', `num1' and `num2' are all fontified with font-lock-variable-name-face. I don't know if this difference demonstrates a bug in python-mode or in python-ts-mode, but I assume only one of them is right. I note that in much online Python documentation variables in assignments or function parameters (with or without type hints) are mostly not fontified (e.g. in Python's own documentation and in https://mypy.readthedocs.io/en/stable/cheat_sheet_py3.html, which is where the examples in the attached file come from). On the other hand, I note that python-ts-mode also fontifies function parameters that lack type hints or default values with font-lock-variable-name-face (the default python-mode does not). In GNU Emacs 30.0.60 (build 3, x86_64-pc-linux-gnu, GTK+ Version 3.24.42, cairo version 1.18.0) of 2024-06-26 built on strobelfs Repository revision: 1809f6a93efe0ab3ac0f62743c92bd90860ff3ea Repository branch: emacs-30 Windowing system distributor 'The X.Org Foundation', version 11.0.12101013 System Description: Linux From Scratch r12.1-85 Configured using: 'configure -C 'CFLAGS=-Og -g3'' Configured features: ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG LCMS2 LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS TREE_SITTER WEBP X11 XDBE XIM XINPUT2 XPM GTK3 ZLIB Important settings: value of $LANG: en_US.UTF-8 locale-coding-system: utf-8-unix