Add lang/python module with uv/ruff/pylsp, ANSI colors, and LSP auto-install

- Add lang/python.el: project detection, ruff format-on-save, C-c C-v -> ruff check,
  optional pylsp with auto-install via uv (asks once per session)
- Fix pylsp resolution to check .venv, uv tool path, and PATH
- Disable legacy pyls client to avoid spurious warnings
- Add ANSI color support in compilation buffers (editor.el)
- Remove python-mode/python-ts-mode from global lsp-deferred hooks (lsp.el)
- Add ruff, ty, uv packages to desktop group_vars

ansible/inventory/group_vars/desktop.yml

@@ -115,8 +115,11 @@ profile_packages:
   - ristretto
   - rsync
   - shotwell
+  - ruff
   - terminus-font
   - texlive
+  - ty
+  - uv
   - Thunar
   - thunar-archive-plugin
   - thunar-volman

dotfiles/desktop/.emacs.d/init.el

@@ -6,13 +6,13 @@
 ;; Load modules
 ;;=====================================================================================
 (fscotto/load-modules
- ;; Core
- 'core/packages
- 'core/ui
- 'core/performance
- 'core/editor
- 'core/keybindings
- 'core/buffer
+  ;; Core
+  'core/packages
+  'core/ui
+  'core/performance
+  'core/editor
+  'core/keybindings
+  'core/buffer
 
   ;; Tools
   'tools/completion
@@ -24,28 +24,29 @@
   'tools/dap
   'tools/treesitter
 
- ;; Languages
- 'lang/c
- 'lang/docker
- 'lang/golang
- 'lang/json
- 'lang/markdown
- 'lang/org
- 'lang/shell
- 'lang/yaml
+  ;; Languages
+  'lang/c
+  'lang/docker
+  'lang/golang
+  'lang/json
+  'lang/markdown
+  'lang/org
+  'lang/python
+  'lang/shell
+  'lang/yaml
 
- ;; Misc
- 'misc/dashboard
- 'misc/custom-functions
- 'misc/doom-modeline
- 'misc/which-key
- 'misc/gptel
- 'misc/email
- 'misc/rss
+  ;; Misc
+  'misc/dashboard
+  'misc/custom-functions
+  'misc/doom-modeline
+  'misc/which-key
+  'misc/gptel
+  'misc/email
+  'misc/rss
   'misc/terminal
   'misc/vcs
   'misc/pdf
   'misc/epub
- 'misc/i3-config)
+  'misc/i3-config)
 
 (message "...user configuration loaded")

dotfiles/desktop/.emacs.d/lisp/core/editor.el

@@ -1,5 +1,7 @@
 ;;; core-editor
 
+(require 'ansi-color)
+
 (setq standard-indent 4)
 (setq tab-stop-list nil)
 (setq indent-tabs-mode nil)
@@ -9,6 +11,8 @@
 (prefer-coding-system 'utf-8-unix)
 (setq custom-file (null-device))
 
+(add-hook 'compilation-filter-hook #'ansi-color-compilation-filter)
+
 (provide 'editor)
 
 ;;; editor.el ends here

dotfiles/desktop/.emacs.d/lisp/lang/python.el

@@ -0,0 +1,135 @@
+;;; python.el -*- lexical-binding: t; -*-
+
+(require 'reformatter)
+
+(with-eval-after-load 'project
+  (add-to-list 'project-vc-extra-root-markers "pyproject.toml")
+  (add-to-list 'project-vc-extra-root-markers "uv.lock")
+  (add-to-list 'project-vc-extra-root-markers ".venv"))
+
+(defun fscotto/python-project-root ()
+  "Return project root for Python projects, nil otherwise."
+  (when (and (featurep 'project)
+             (project-current))
+    (let ((root (project-root (project-current))))
+      (when (or (file-exists-p (expand-file-name "pyproject.toml" root))
+                (file-exists-p (expand-file-name "uv.lock" root)))
+        root))))
+
+(defun fscotto/python-project-has-uv-p ()
+  "Return t if current project uses uv (pyproject.toml or uv.lock)."
+  (when-let ((root (fscotto/python-project-root)))
+    (or (file-exists-p (expand-file-name "uv.lock" root))
+        (file-exists-p (expand-file-name "pyproject.toml" root)))))
+
+(defun fscotto/python-project-bin (tool)
+  "Return path to TOOL in .venv/bin if it exists, else nil."
+  (when-let ((root (fscotto/python-project-root)))
+    (let ((venv-bin (expand-file-name (concat ".venv/bin/" tool) root)))
+      (when (and (file-exists-p venv-bin)
+                 (file-executable-p venv-bin))
+        venv-bin))))
+
+(defun fscotto/python-activate-project-tools ()
+  "Prefer tools from the project virtualenv when available."
+  (when-let* ((root (fscotto/python-project-root))
+              (venv-bin (expand-file-name ".venv/bin" root))
+              ((file-directory-p venv-bin)))
+    (make-local-variable 'exec-path)
+    (add-to-list 'exec-path venv-bin)
+    (setq-local process-environment (copy-sequence process-environment))
+    (setenv "PATH" (concat venv-bin path-separator (getenv "PATH")))))
+
+(defvar fscotto/python-lsp-install-asked nil
+  "Non-nil if user was already asked about installing pylsp this session.")
+
+(defun fscotto/resolve-pylsp ()
+  "Return the pylsp binary path if found, else nil.
+Checks: project .venv, uv tool install path, and PATH."
+  (or (fscotto/python-project-bin "pylsp")
+      (let ((uv-pylsp (expand-file-name "pylsp"
+                                        (concat (getenv "HOME")
+                                                "/.local/share/uv/tools/python-lsp-server/bin"))))
+        (when (and (file-exists-p uv-pylsp)
+                   (file-executable-p uv-pylsp))
+          uv-pylsp))
+      (executable-find "pylsp")))
+
+(defun fscotto/python-lsp-server-available-p ()
+  "Return non-nil when a supported Python LSP server is available."
+  (fscotto/resolve-pylsp))
+
+(defun fscotto/python-ensure-lsp-server ()
+  "Ensure a Python LSP server is installed, prompting the user if needed.
+If pylsp is already available, start LSP immediately. Otherwise, ask once
+whether to install it via uv. On confirmation, install python-lsp-server
+as a uv tool and then start LSP."
+  (unless (fboundp 'lsp-deferred)
+    (message "python: lsp-mode not available")
+    (return-from fscotto/python-ensure-lsp-server))
+
+  (if (fscotto/python-lsp-server-available-p)
+      (progn
+        (setq lsp-pylsp-server-command (fscotto/resolve-pylsp))
+        (lsp-deferred))
+    (when (or fscotto/python-lsp-install-asked
+              (y-or-n-p "python-lsp-server not found. Install it via uv? "))
+      (setq fscotto/python-lsp-install-asked t)
+      (let ((buf (current-buffer)))
+        (message "Installing python-lsp-server via uv in background...")
+        (make-process
+         :name "uv-pylsp-install"
+         :buffer (get-buffer-create " *uv-pylsp-install*")
+         :command '("uv" "tool" "install" "--upgrade" "python-lsp-server")
+         :sentinel
+         (lambda (proc event)
+           (cond
+            ((string-match-p "finished" event)
+             (message "python-lsp-server installed.")
+             (setq lsp-pylsp-server-command (fscotto/resolve-pylsp))
+             (with-current-buffer buf
+               (lsp-deferred)))
+            ((string-match-p "exited\\|failed" event)
+             (with-current-buffer buf
+               (message "python-lsp-server installation failed. Check *uv-pylsp-install* buffer."))))))))))
+
+(defun fscotto/python-maybe-start-lsp ()
+  "Start Python LSP, installing pylsp via uv if needed."
+  (fscotto/python-ensure-lsp-server))
+
+(defun fscotto/python-setup-check-command ()
+  "Use Ruff for the built-in Python check command."
+  (setq-local python-check-command "ruff check"))
+
+(reformatter-define fscotto/ruff-format
+  :program (or (fscotto/python-project-bin "ruff") (executable-find "ruff"))
+  :args '("format" "-")
+  :lighter " ruff")
+
+(with-eval-after-load 'python
+  (add-hook 'python-mode-hook #'fscotto/python-activate-project-tools)
+  (add-hook 'python-mode-hook #'fscotto/python-setup-check-command)
+  (add-hook 'python-mode-hook #'fscotto/ruff-format-on-save-mode)
+  (add-hook 'python-mode-hook #'fscotto/python-maybe-start-lsp))
+
+(with-eval-after-load 'python-ts-mode
+  (add-hook 'python-ts-mode-hook #'fscotto/python-activate-project-tools)
+  (add-hook 'python-ts-mode-hook #'fscotto/python-setup-check-command)
+  (add-hook 'python-ts-mode-hook #'fscotto/ruff-format-on-save-mode)
+  (add-hook 'python-ts-mode-hook #'fscotto/python-maybe-start-lsp))
+
+(with-eval-after-load 'lsp-mode
+  (add-to-list 'lsp-language-id-configuration '(python-mode . "python"))
+  (add-to-list 'lsp-language-id-configuration '(python-ts-mode . "python"))
+  (setq lsp-pylsp-server-command (fscotto/resolve-pylsp))
+  (setq lsp-pylsp-plugins
+        '((pycodestyle nil)
+          (pyflakes nil)
+          (mccabe nil)
+          (autopep8 nil)
+          (yapf nil)))
+  (add-to-list 'lsp-disabled-clients 'pyls))
+
+(provide 'lang/python)
+
+;;; python.el ends here

dotfiles/desktop/.emacs.d/lisp/tools/lsp.el

@@ -8,8 +8,6 @@
     c-ts-mode
     c++-mode
     c++-ts-mode
-    python-mode
-    python-ts-mode
     sh-mode
     bash-ts-mode) . lsp-deferred)
   :config