Automatically Remove Unused Imports & Variables From Python

Unused code will distract you(and other people) while reading code. Also, a single unused import can cause out of memory error. So, it is considered as a bad practice. Lets try to get rid of unused imports & variables from Python code.

Autoflake removes unused imports and unused variables as reported by pyflakes. Install it

pip install --upgrade autoflake    

Now select a file which you want to clean and run this in terminal

autoflake --in-place --remove-unused-variables example.py

It removes all unused imports & variables from the file.

Instead of running this command every time, I wrote a simple elisp function and assigned a F8 key to that function. So while writing the code itself it can clean it & it's much efficient.

;; Py-rm - Remove unused variables & imports from python

(defun pyrm ()

  (interactive)

  (setq command (concatenate 'string "autoflake --in-place --remove-unused-variables " buffer-file-name))

  (shell-command command)

  ;; Reload the modified file

  (revert-buffer t t)

  )

;; set a custom key for pyrm

(global-set-key [f8] 'pyrm)

Put the above code in your emacs configuration file, restart it & press F8 whenever you want to clean the code.

However, if you just need to highlight but not delete them, you can install flymake and then enter this.

M-x flymake-mode RET 

It just highlights the other syntax errors and unused imports but won't delete them.

Screenshots:

Simple Python Code

Highlighted with flymake-mode

Cleaned with autoflake