bug#21242: 24.5.1; python.el: should display output buffer on exceptions when using python-shell-send-region

bug#21242: 24.5.1; python.el: should display output buffer on exceptions when using python-shell-send-region

[Yuri D'Elia]

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When evaluating the code interactively, there's currently no
notification about evaluation errors. Exceptions in the output buffer go
simply unnoticed, unless you watch for them closely. I like to keep the
output buffer buried, and assume that no-notification==no-error.

Exceptions caused by interactive evaluation should either:

- show a notification of sorts in the minibuffer
- display the output buffer for inspection

For inspiration about the second, see:

https://github.com/wavexx/python-x.el/blob/master/python-x.el#L424

Given previous experience with python-mode.el (which tends to break the
current window layout with his own splitting logic), I find it important
that the notification function (which displays the output buffer) should
be customizable, and this is reflected in the example code.

[-- Attachment #2: python-buffer-substring.patch --]
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--- python.el.Orig	2015-07-18 18:00:49.367517569 +0200
+++ python.el	2015-07-18 18:03:01.203659502 +0200
@@ -2548,18 +2548,22 @@
                      (make-string
                       ;; Subtract 2 because of the coding cookie.
                       (- (line-number-at-pos start) 2) ?\n))))
-         (toplevel-block-p (save-excursion
-                             (goto-char start)
-                             (or (zerop (line-number-at-pos start))
-                                 (progn
-                                   (python-util-forward-comment 1)
-                                   (zerop (current-indentation)))))))
+         (block-param (save-excursion
+                        (goto-char start)
+                        (progn
+                          (python-util-forward-comment 1)
+                          (list (current-indentation)
+                                (/= (point) start)))))
+         (block-indentation (car block-param))
+         (starts-with-indentation-p (cadr block-param)))
     (with-temp-buffer
       (python-mode)
       (if fillstr (insert fillstr))
+      (when (and (> block-indentation 0) (not starts-with-indentation-p))
+        (insert (make-string block-indentation ?\s)))
       (insert substring)
       (goto-char (point-min))
-      (when (not toplevel-block-p)
+      (when (> block-indentation 0)
         (insert "if True:")
         (delete-region (point) (line-end-position)))
       (when nomain

bug#21242: 24.5.1; python.el: should display output buffer on exceptions when using python-shell-send-region

[Andreas Röhler]

Am 12.08.2015 um 16:05 schrieb Yuri D'Elia:
> When evaluating the code interactively, there's currently no
> notification about evaluation errors. Exceptions in the output buffer go
> simply unnoticed, unless you watch for them closely. I like to keep the
> output buffer buried, and assume that no-notification==no-error.
>
> Exceptions caused by interactive evaluation should either:
>
> - show a notification of sorts in the minibuffer
> - display the output buffer for inspection
>
> For inspiration about the second, see:
>
> https://github.com/wavexx/python-x.el/blob/master/python-x.el#L424
>
> Given previous experience with python-mode.el (which tends to break the
> current window layout with his own splitting logic), I find it important
> that the notification function (which displays the output buffer) should
> be customizable, and this is reflected in the example code.

WRT python-mode.el:

Splitting-behavior _is_ customizable. It only occurs if 
py-split-window-on-execute is non-nil - default is 'just-two.
Also there is py-keep-windows-configuration, when non-nil it precedes 
other settings.

bug#21242: 24.5.1; python.el: should display output buffer on exceptions when using python-shell-send-region

[Lars Ingebrigtsen]

Yuri D'Elia <wavexx@thregr.org> writes:

> When evaluating the code interactively, there's currently no
> notification about evaluation errors. Exceptions in the output buffer go
> simply unnoticed, unless you watch for them closely. I like to keep the
> output buffer buried, and assume that no-notification==no-error.
>
> Exceptions caused by interactive evaluation should either:
>
> - show a notification of sorts in the minibuffer
> - display the output buffer for inspection

I don't use this stuff a lot, but I just don't understand how the patch
attached relates to the reported problem.

And there's also Andreas's comment (at the end).

Yuri, could you explain a bit more about how this patch fixes the
problem?

> -         (toplevel-block-p (save-excursion
> -                             (goto-char start)
> -                             (or (zerop (line-number-at-pos start))
> -                                 (progn
> -                                   (python-util-forward-comment 1)
> -                                   (zerop (current-indentation)))))))
> +         (block-param (save-excursion
> +                        (goto-char start)
> +                        (progn
> +                          (python-util-forward-comment 1)
> +                          (list (current-indentation)
> +                                (/= (point) start)))))
> +         (block-indentation (car block-param))
> +         (starts-with-indentation-p (cadr block-param)))
>      (with-temp-buffer
>        (python-mode)
>        (if fillstr (insert fillstr))
> +      (when (and (> block-indentation 0) (not starts-with-indentation-p))
> +        (insert (make-string block-indentation ?\s)))
>        (insert substring)
>        (goto-char (point-min))
> -      (when (not toplevel-block-p)
> +      (when (> block-indentation 0)
>          (insert "if True:")
>          (delete-region (point) (line-end-position)))

Andreas Röhler <andreas.roehler@easy-emacs.de> writes:

>> Given previous experience with python-mode.el (which tends to break the
>> current window layout with his own splitting logic), I find it important
>> that the notification function (which displays the output buffer) should
>> be customizable, and this is reflected in the example code.
>
> WRT python-mode.el:
>
> Splitting-behavior _is_ customizable. It only occurs if
> py-split-window-on-execute is non-nil - default is 'just-two.
> Also there is py-keep-windows-configuration, when non-nil it precedes
> other settings.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#21242: 24.5.1; python.el: should display output buffer on exceptions when using python-shell-send-region

[Yuri D'Elia]

On Thu, Sep 17 2020, Lars Ingebrigtsen wrote:
> I don't use this stuff a lot, but I just don't understand how the patch
> attached relates to the reported problem.
>
> And there's also Andreas's comment (at the end).
>
> Yuri, could you explain a bit more about how this patch fixes the
> problem?

I won't lie here, I have _no_ clue anymore what I had in mind with that
code at a first glance.

bug#21242: 24.5.1; python.el: should display output buffer on exceptions when using python-shell-send-region

[Lars Ingebrigtsen]

Yuri D'Elia <wavexx@thregr.org> writes:

>> Yuri, could you explain a bit more about how this patch fixes the
>> problem?
>
> I won't lie here, I have _no_ clue anymore what I had in mind with that
> code at a first glance.

:-)

But it sounds like there probably won't be more progress here in this
bug report, then, so I'm closing it.  If further progress can be made,
please respond to the debbugs address, and we'll reopen.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no