   (ignore start stop len)
   (if live-py-timer
       (cancel-timer live-py-timer)
-    (setq-local live-py-lighter " Live-D") ; D for delaying
-    ;; Here it seems not necessary to `force-mode-line-update'.
-    (redisplay))
+    (when live-py-lighter-delaying
+      (setq-local live-py-lighter live-py-lighter-delaying)
+      ;; Here it seems not necessary to `force-mode-line-update'.
+      (redisplay)))
   (setq-local live-py-timer (run-at-time 0.5 nil 'live-py-trace-update)))
 
 (defun live-py-trace-update ()
   "Trace the Python code using code_tracer.py."
   ;; For when called from elsewhere than `live-py-after-change-function'.
   (when live-py-timer (cancel-timer live-py-timer))
-  (setq-local live-py-lighter " Live-T") ; T for tracing
-  (force-mode-line-update)
-  (redisplay)
+  (when live-py-lighter-tracing
+    (setq-local live-py-lighter live-py-lighter-tracing)
+    (force-mode-line-update)
+    (redisplay))
   (let* ((tracer-path (locate-file "code_tracer.py" load-path))
          (command-line-start (concat
 			      (shell-quote-argument live-py-version)

(defvar live-py-dir nil)
(defvar live-py-path nil)
(defvar live-py-version nil)

;; Internal variables.
(defvar live-py-output-window nil)

                       t))))

  (unless (string-prefix-p live-py-dir buffer-file-name)
    (user-error "Working directory %s must be a parent of %s"
		live-py-dir
		buffer-file-name))
  (setq-local live-py-module (file-name-base buffer-file-name))
