Improve python venv handling

emacs/init.org

@@ -2820,8 +2820,8 @@ Emacs support for the Language Server Protocol
 #+END_SRC
 
 * Python
+** General
 #+BEGIN_SRC emacs-lisp
-  ;; (leader-def-key "sp" #'elpy-shell-switch-to-shell)
   (leader-def-key "sp" #'run-python)
   (add-hook 'python-mode-hook #'disable-tab-insert)
 #+END_SRC
@@ -2845,37 +2845,6 @@ Font-lock for f-strings:
 		      (0 font-lock-variable-name-face t)))))))
 #+END_SRC
 
-
-Elpy is a python IDE package:
-#+BEGIN_SRC emacs-lisp :tangle no
-  (use-package elpy
-    :init (elpy-enable)
-    :config (setq elpy-rpc-python-command "python3"))
-#+END_SRC
-
-Alternatively, use the LSP python client:
-#+BEGIN_SRC emacs-lisp
-  (add-hook 'python-mode-hook #'lsp-deferred)
-  (general-def 'normal python-mode-map "C-c C-d" #'lsp-describe-thing-at-point)
-#+END_SRC
-
-Support pyvenv within Emacs:
-#+BEGIN_SRC emacs-lisp
-  (use-package pyvenv
-    :commands (pyvenv-mode pyvenv-workon pyvenv-activate)
-    :init
-    (add-hook 'after-init-hook #'pyvenv-mode))
-
-  (defun eshell/workon (name)
-    (pyvenv-workon name))
-
-  (defun eshell/activate (dir)
-    (pyvenv-activate dir))
-
-  (defun eshell/deactivate ()
-    (pyvenv-deactivate))
-#+END_SRC
-
 ISort is a Python utility to sort imports:
 #+BEGIN_SRC emacs-lisp
   (use-package py-isort
@@ -2886,24 +2855,6 @@ ISort is a Python utility to sort imports:
     (python-mode-map "C-c C-i" #'py-isort-buffer))
 #+END_SRC
 
-Pipenv is the Python standard dependency management/virtual environment tool. pipenv.el teaches Emacs its ways:
-#+BEGIN_SRC emacs-lisp
-  (use-package pipenv
-    :hook (python-mode . pipenv-mode)
-    :commands (pipenv-mode
-	       pipenv-activate
-	       pipenv-run))
-#+END_SRC
-
-A function to run a pipenv-aware python repl:
-#+BEGIN_SRC emacs-lisp
-  (defun run-pipenv ()
-    "Runs a pipenv-aware Python shell"
-    (interactive)
-    (pipenv-activate)
-    (run-python nil nil t))
-#+END_SRC
-
 Run black on the current buffer:
 #+BEGIN_SRC emacs-lisp
   (general-def 'normal python-mode-map "C-M-\\" #'format-all-buffer)
@@ -2915,12 +2866,126 @@ Run black on the current buffer:
     :hook ((python-mode . sphinx-doc-mode)))
 #+END_SRC
 
+** Dev environment/IDE stuff
+Support pyvenv within Emacs:
+#+BEGIN_SRC emacs-lisp
+  (use-package pyvenv
+    :commands (pyvenv-mode
+               pyvenv-workon
+               pyvenv-activate
+               pyvenv-track-virtualenv))
+
+  (defun eshell/workon (name)
+    (pyvenv-workon name))
+
+  (defun eshell/activate (dir)
+    (pyvenv-activate dir))
+
+  (defun eshell/deactivate ()
+    (pyvenv-deactivate))
+#+END_SRC
+
+Pipenv is a dependency management/virtual environment tool. pipenv.el teaches Emacs its ways:
+#+BEGIN_SRC emacs-lisp
+  (use-package pipenv
+    :commands (pipenv-mode
+               pipenv-activate
+               pipenv-run)
+    :custom
+    (pipenv-with-projectile nil)
+    (pipenv-with-flycheck nil))
+#+END_SRC
+
 And support pyenv (NOT pyvenv) to change Python versions:
 #+BEGIN_SRC emacs-lisp
   (use-package pyenv-mode
     :defer t)
 #+END_SRC
 
+Add a hook to set the correct python for the current buffer:
+#+BEGIN_SRC emacs-lisp
+  (defvar python-buffer-venv nil)
+  (make-variable-buffer-local 'python-buffer-venv)
+
+  (defun save-buffer-venv (&rest args)
+    (setq python-buffer-venv pyvenv-virtual-env))
+
+  (advice-add 'pyvenv-activate :after #'save-buffer-venv)
+  (advice-add 'pyvenv-workon :after #'save-buffer-venv)
+  (advice-add 'pyvenv-track-virtualenv :after #'save-buffer-venv)
+
+  (defun activate-buffer-venv ()
+    "Activates the virtualenv that was previously set in this buffer."
+    (when (and python-buffer-venv
+               (not (eq python-buffer-venv pyvenv-virtual-env)))
+      (pyvenv-activate python-buffer-venv)))
+
+  (defun maybe-activate-venv ()
+    "Activates the virtual env for the current buffer if one exists.
+    Returns `t' if a venv was activated."
+    (interactive)
+    (cond
+     ((pipenv-activate) t)
+     ((or pyvenv-activate pyvenv-workon)
+      (progn (pyvenv-track-virtualenv) t))))
+
+  (defun activate-venv-post-command ()
+    (ignore-errors (activate-buffer-venv)))
+
+  (define-minor-mode python-env-mode
+    "Global minor mode to track Python environment."
+    :global t
+    (cond
+     (python-env-mode
+      (add-to-list 'mode-line-misc-info '(python-env-mode pyvenv-mode-line-indicator))
+      (add-hook 'hack-local-variables-hook #'maybe-activate-venv)
+      (add-hook 'post-command-hook #'activate-venv-post-command))
+     ((not python-env-mode)
+      (setq mode-line-misc-info (delete '(python-env-mode pyvenv-mode-line-indicator)
+                                        mode-line-misc-info))
+      (remove-hook 'hack-local-variable-hook #'maybe-activate-venv)
+      (remove-hook 'post-command-hook #'activate-venv-post-command))))
+
+  (add-hook 'after-init-hook #'python-env-mode)
+#+END_SRC
+
+Use the LSP python client:
+#+BEGIN_SRC emacs-lisp
+  (defun python-lsp ()
+    "Activates the project virtualenv if one exists then runs LSP."
+    (interactive)
+    (maybe-activate-venv)
+    (lsp-deferred))
+
+  (add-hook 'python-mode-hook #'python-lsp)
+
+  (general-def 'normal python-mode-map "C-c C-d" #'lsp-describe-thing-at-point)
+#+END_SRC
+
+Fix the doom-modeline Python display for Pipenv projects:
+#+BEGIN_SRC emacs-lisp
+  (with-eval-after-load 'doom-modeline-env
+    (doom-modeline-def-env python
+      :hooks   'python-mode-hook
+      :command (lambda ()
+                 (let ((old (getenv "PIPENV_VERBOSITY")))
+                   (setenv "PIPENV_VERBOSITY" "-1")
+                   (cond ((and (fboundp 'pipenv-project-p)
+                               (pipenv-project-p))
+                          (list "pipenv" "run"
+                                (or doom-modeline-env-python-executable
+                                    python-shell-interpreter
+                                    "python")
+                                "--version"))
+                         ((list (or doom-modeline-env-python-executable
+                                    python-shell-interpreter
+                                    "python")
+                                "--version")))
+                   (setenv "PIPENV_VERBOSITY" old)))
+      :parser  (lambda (line) (cadr (split-string line)))))
+#+END_SRC
+
+
 ** Autoflake
 [[https://pypi.org/project/autoflake/][Autoflake]] is a tool that removes unused imports and variables from Python code:
 #+BEGIN_SRC emacs-lisp