importmagic.el

importmagic.el is an Emacs package inspired on @alecthomas's importmagic library and PyCharm's ability to suggest imports for unresolved symbols.

WARNING!

PLEASE use wrappers for virtual environments as importmagic.el does not care at all about the environment on which it is run. importmagic.el is known to work with virtualenvwrapper.el and pyvenv.

If you still don't want to do that, check out the Usage section.

Installation

To install this package, MELPA is the way to go, but you also need some extra dependencies.

Python dependencies

This package relies heavily on importmagic and EPC. You can get them from pip. These packages should be installed in the same environment you're working on.

$ pip install importmagic epc

Installing the Emacs package

It is recommended that you install this package from MELPA. There's still a way if you don't use it though.

From MELPA

A simple way would be to just:

M-x package-install RET importmagic RET

You can also try use-package:

(use-package importmagic
    :ensure t
    :config
    (add-hook 'python-mode-hook 'importmagic-mode))

The above example is the minimal configuration in order to get started with importmagic.

Whichever way you choose remember to add the hook to python mode:

(add-hook 'python-mode-hook 'importmagic-mode)

Without MELPA

Download both importmagic.el and importmagicserver.py. Place them on a load-path of your emacs directory. For instance: ~/.emacs.d/site-lisp

If you haven't already, tell emacs you want to load files from that directory:

(add-to-list 'load-path (expand-file-name (concat user-emacs-directory "site-lisp/")))

Of course, you can choose to change the name of the site-lisp portion of the code. Don't forget to add the mode to Python buffers, put this line anywhere in your .emacs or init.el

(add-hook 'python-mode-hook 'importmagic-mode)

Usage

The default behavior sets only one key binding: C-c C-l. It solves imports for every unresolved symbol in the buffer, prompting for one import at a time. If there are no imports found for a given symbol, importmagic will let you know at the end of the process.

By default, importmagic.el will recursively index every symbol from the current buffer's directory, which means you should get fairly accurate suggestions for imports you might need.

Key bindings

Every key binding is under the importmagic-mode-map. If you don't like the C-c C-l keybinding or want to add extra keys to your configuration, just set them like so:

(define-key importmagic-mode-map (kbd "C-c C-f") 'importmagic-fix-symbol-at-point)

Note that the example above will override a defined key binding in the python-mode-map. You can do that as long as you feel the need to (as I did). This package is not really intended to interfere with the default bindings, though.

Imports style

Importmagic supports configuration on the styles it has. As of July 2, 2017, so does importmagic.el.

When an import statement gets too long, you have the choice to group it using either parentheses or backslashes. Both of these options (maximum length of line and import group styles) can be set with the variable importmagic-configuration-style-alist, which is an alist (duh) of your preferences.

The default value is

'((multiline . parentheses)
  (max_columns . 79))

Customizing

M-x customize-group RET importmagic RET.

Python Interpreter

As we talked about in the first section of this document, importmagic.el won't care about the environment and will use the default system python interpreter. If you do not want to do this and want to use a different python interpreter you can set importmagic-python-interpreter like so:

(setq importmagic-python-interpreter "/path/to/my/virtualenv/bin/python")

Annoyances

Every package has its own annoyances, and this one is no exception. I'll try to describe here how to get rid of annoyances this package may produce.

Non-error messages

importmagic.el can be very verbose when you develop Python for several hours. In fact, it was suggested that I gave the possibility to supress these messages. You can do so by setting the variable importmagic-be-quiet to t like so:

(setq importmagic-be-quiet t)

This, however, will not supress error messages.

Mode line

If importmagic gets your mode line too cluttered, try diminish. Something like this would be fine:

(diminish 'importmagic-mode)

Buffers

importmagic.el uses an EPC server to query for symbols. While it's very convenient for the developer, it's not so good for the user, because it generates one buffer with the EPC connection for every Python buffer you open. While that's ok (at least for me), It can be troublesome for some people.

Helm users can get rid of these buffers (as in not see them) by evaluating the following expression:

(add-to-list 'helm-boring-buffer-regexp-list "\\*epc con")

Likewise, ivy users can get rid of it with the following:

(add-to-list 'ivy-ignore-buffers "\\*epc con")

For ido users, no idea, Sorry!

Provided functions

A list of every provided function, in case you either want to bind them to a key or just want to M-x for it.

importmagic-mode

Turn on/off importmagic-mode in the current buffer. As usual, a positive argument sets it on and a negative argument sets it off. With just M-x, it will toggle the mode.

importmagic-fix-imports

Query for every unimported symbol in the current buffer. This can be useful if you've written a lot of code and didn't bother to import anything.

importmagic-fix-symbol-at-point

Query for imports for the symbol at point. Note that this will query the database even if the symbol at point is already imported. Flycheck can be helpful for this one.

importmagic-fix-symbol

Prompts for a symbol to import. This function is the base for the two above since it doesn't make any assumption on what you want to import. It will find suitable candidates for the given symbol. Note that it can import symbols that you're not currently using.

importmagic-update-index

Updates index for the current file. This can be useful if something changed in the current directory outside the current buffer and you need to import symbols from those modified files.

Virtual environments

importmagic.el is known to work with pyvenv and virtualenvwrapper.el. Other packages have not been tested.

Note that the above will mean that if either importmagic or epc are not in your virtual env, it will fail. Don't worry too much though. If importmagic fails, it will give you a warning, but it will not get in your way.

Known issues

There seems to be an issue going on with Gtk symbols. It doesn't only affect importmagic, but it also affects Jedi. See this issue.

Contributing

Any kind of contribution is absolutely welcome.

If you haven't already, install Cask. Run the tests with:

$ cask exec ert-runner

Note that you'll need ert-runner for that.

Send me pull-requests!