How do I set Emacs tab size to 4 chars wide for .py files?

Question

I've tried using the following:

(setq-default tab-width 4)
(setq-default tab-stop-list (list 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60))

But the size of tabs when editing .py files is still 8 chars wide. In other files it has gone down to 4, so I assume the Python major mode is overriding this somehow. I see that I can set python-indent to 4, but this causes spaces to be inserted (which goes against our code style guide).

How do I make the tabs 4 chars in width?

Update:

I've also tried this, but it didn't do anything:

(add-hook 'python-mode-hook
  (setq indent-tabs-mode t)
  (setq tab-width 4)
)

Answer 1

(setq indent-tabs-mode t)
(setq python-indent 4)

Answer 2

I've had that same issue, but with C++ files. What finally did it for me was the following in my .emacs.

(custom-set-variables
;; custom-set-variables was added by Custom.
;; If you edit it by hand, you could mess it up, so be careful.
;; Your init file should contain only one such instance.
;; If there is more than one, they won't work right.
'(c-basic-offset 4 t)
)

Actually of course I set it from the C++ mode area of the Customize Emacs menu, but this was the result. I'd see if python mode has something similar. py-basic-offset or something? Surf around the mode settings for pyton.

Answer 3

The correct form for the hook is this:

(add-hook 'python-mode-hook
          (lambda ()
            (setq indent-tabs-mode t)
            (setq tab-width 4)))

You need to put the imperative statements inside a function (lambda).

Answer 4

(add-hook 'python-mode-hook
      (lambda ()
        (setq indent-tabs-mode t)
        (setq tab-width 4)
        (setq python-indent 4)))