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PyLint "Unable to import" error - how to set PYTHONPATH?

I'm running PyLint from inside Wing IDE on Windows. I have a sub-directory (package) in my project and inside the package I import a module from the top level, ie.

__init__.py
myapp.py
one.py
subdir\
    __init__.py
    two.py

Inside two.py I have import one and this works fine at runtime, because the top-level directory (from which myapp.py is run) is in the Python path. However, when I run PyLint on two.py it gives me an error:

F0401: Unable to import 'one'

How do I fix this?


M
Muhammad Dyas Yaskur

There are two options I'm aware of.

One, change the PYTHONPATH environment variable to include the directory above your module.

Alternatively, edit ~/.pylintrc to include the directory above your module, like this:

[MASTER]
init-hook='import sys; sys.path.append("/path/to/root")'

(Or in other version of pylint, the init-hook requires you to change [General] to [MASTER])

Both of these options ought to work.


This pylint hook is currently the best way in VScode as PYTHONPATH isn't yet supported for it's built in linter usage.
I have the same issue using MacVim with syntastic. How can I configure prosector to fix the import error ?
Related blog post with a few more details.
~/.pylintrc worked for me on OSX, the other didn't work
Not sure why this is not the accepted answer - also, worth mentioning for those stumbling on this, that you need to export PYTHONPATH so that pylint will see it (at least, in bash/zsh)
A
Asclepius

The solution to alter path in init-hook is good, but I dislike the fact that I had to add absolute path there, as result I can not share this pylintrc file among the developers of the project. This solution using relative path to pylintrc file works better for me:

[MASTER]
init-hook="from pylint.config import find_pylintrc; import os, sys; sys.path.append(os.path.dirname(find_pylintrc()))"

Note that pylint.config.PYLINTRC also exists and has the same value as find_pylintrc().


Confirming that this really did supply the solution for E0611 and E0401 pylint errors. For VSCode users: It is important the the opened folder is the "python root folder", and that the .pylintrc is in that folder.
also, make sure none of your module directory names start with . (dot).
if you want to add a specific sub-folder (i.e. app) you can use from pylint.config import find_pylintrc; import os, sys; sys.path.append(os.path.join(os.path.dirname(find_pylintrc()), 'app'))
In my setup the package in question was outside the root of the project, therefore my line looks like this: init-hook="from pylint.config import find_pylintrc; import os, sys; sys.path.append(os.path.join(os.path.dirname(find_pylintrc()),".."))"
This works perfectly, even during Jenkins CI
j
jeanerpp

The problem can be solved by configuring pylint path under venv: $ cat .vscode/settings.json

{
    "python.pythonPath": "venv/bin/python",
    "python.linting.pylintPath": "venv/bin/pylint"
}

For Windows it's { "python.pythonPath": "${workspaceFolder}\\.venv\\Scripts\\python.exe" "python.linting.pylintPath": "${workspaceFolder}\\.venv\\Scripts\\pylint.exe" } Just for completeness.
VSCode now shows this message: The setting "python.pythonPath" defined in your settings.json is now deprecated. If I delete the python.pythonPath line it still seems to work though.
Simple as that. That sounds way better than altering import paths. That works perfectly for anyone using poetry (which creates its virtual environment in .venv/ by default): "python.linting.pylintPath": "${workspaceFolder}/.venv/bin/pylint",
Adding "python.linting.pylintPath": "venv/bin/pylint" was enough to me, although I already had pythonPath set
This doesn't look related to the OP. It says nothing about a vscode-specific implementation.
u
unmounted

Do you have an empty __init__.py file in both directories to let python know that the dirs are modules?

The basic outline when you are not running from within the folder (ie maybe from pylint's, though I haven't used that) is:

topdir\
  __init__.py
  functions_etc.py
  subdir\
    __init__.py
    other_functions.py

This is how the python interpreter is aware of the module without reference to the current directory, so if pylint is running from its own absolute path it will be able to access functions_etc.py as topdir.functions_etc or topdir.subdir.other_functions, provided topdir is on the PYTHONPATH.

UPDATE: If the problem is not the __init__.py file, maybe just try copying or moving your module to c:\Python26\Lib\site-packages -- that is a common place to put additional packages, and will definitely be on your pythonpath. If you know how to do Windows symbolic links or the equivalent (I don't!), you could do that instead. There are many more options here: http://docs.python.org/install/index.html, including the option of appending sys.path with the user-level directory of your development code, but in practice I usually just symbolically link my local development dir to site-packages - copying it over has the same effect.


Yes, I do have __init__.py in both directories. I think the problem is that the top dir is NOT in PYTHONPATH when PyLint runs and I'm not sure how to fix that.
The symlink is a good idea, but it's only supported from Windows Vista onwards and I'm running XP. I suppose I could try hard-linking it...
re hardlinking: No, you better don't do it. I've played with it and, while it certainly works (in a way), it will not work as you expect.
Symlinks are not a good idea. This only fixes the problem on your machine - when someone else checks out the project, it will be broken for them.
x
x-magix

general answer for this question I found on this page PLEASE NOT OPEN, SITE IS BUGED

create .pylintrc and add

[MASTER]
init-hook="from pylint.config import find_pylintrc;
import os, sys; sys.path.append(os.path.dirname(find_pylintrc()))"

This link name perplexes me
I would add that this file should be placed in the directory that you want added to PYTHONPATH. Also, this only worked for me if the double-quoted commands are on a single line instead of two, as above.
A
Asclepius

1) sys.path is a list.

2) The problem is sometimes the sys.path is not your virtualenv.path and you want to use pylint in your virtualenv

3) So like said, use init-hook (pay attention in ' and " the parse of pylint is strict)

[Master]
init-hook='sys.path = ["/path/myapps/bin/", "/path/to/myapps/lib/python3.3/site-packages/", ... many paths here])'

or

[Master]
init-hook='sys.path = list(); sys.path.append("/path/to/foo")'

.. and

pylint --rcfile /path/to/pylintrc /path/to/module.py

m
muTheTechie

I've added a new file pylintrc in the project's root directory with

[MASTER]
init-hook='import sys; sys.path.append(".")'

and it works for me in PyCharm IDE


Works for me in VS Code also. Thanks!
This is the only answer that work on my computer. I tried other answers above but doesn't work.
s
simon

I don't know how it works with WingIDE, but for using PyLint with Geany, I set my external command to:

PYTHONPATH=${PYTHONPATH}:$(dirname %d) pylint --output-format=parseable --reports=n "%f"

where %f is the filename, and %d is the path. Might be useful for someone :)


J
JAB

Try

if __name__ == '__main__': from [whatever the name of your package is] import one else: import one Note that in Python 3, the syntax for the part in the else clause would be from .. import one

On second thought, this probably won't fix your specific problem. I misunderstood the question and thought that two.py was being run as the main module, but that is not the case. And considering the differences in the way Python 2.6 (without importing absolute_import from __future__) and Python 3.x handle imports, you wouldn't need to do this for Python 2.6 anyway, I don't think.

Still, if you do eventually switch to Python 3 and plan on using a module as both a package module and as a standalone script inside the package, it may be a good idea to keep something like

if __name__ == '__main__':
    from [whatever the name of your package is] import one   # assuming the package is in the current working directory or a subdirectory of PYTHONPATH
else:
    from .. import one

in mind.

EDIT: And now for a possible solution to your actual problem. Either run PyLint from the directory containing your one module (via the command line, perhaps), or put the following code somewhere when running PyLint:

import os

olddir = os.getcwd()
os.chdir([path_of_directory_containing_module_one])
import one
os.chdir(olddir)

Basically, as an alternative to fiddling with PYTHONPATH, just make sure the current working directory is the directory containing one.py when you do the import.

(Looking at Brian's answer, you could probably assign the previous code to init_hook, but if you're going to do that then you could simply do the appending to sys.path that he does, which is slightly more elegant than my solution.)


B
Brian Moeskau

I had to update the system PYTHONPATH variable to add my App Engine path. In my case I just had to edit my ~/.bashrc file and add the following line:

export PYTHONPATH=$PYTHONPATH:/path/to/google_appengine_folder

In fact, I tried setting the init-hook first but this did not resolve the issue consistently across my code base (not sure why). Once I added it to the system path (probably a good idea in general) my issues went away.


N
Nate

I had this same issue and fixed it by installing pylint in my virtualenv and then adding a .pylintrc file to my project directory with the following in the file:

[Master]
init-hook='sys.path = list(); sys.path.append("./Lib/site-packages/")'

I have to confirm that this gets rid of the E0611 pylint errors, but the E0401 errors remain.
Z
Zain Aftab

I found a nice answer. Edit your pylintrc and add the following in master

init-hook="import imp, os; from pylint.config import find_pylintrc; imp.load_source('import_hook', os.path.join(os.path.dirname(find_pylintrc()), 'import_hook.py'))"

N
Nadeem

When you install Python, you can set up the path. If path is already defined then what you can do is within VS Code, hit Ctrl+Shift+P and type Python: Select Interpreter and select updated version of Python. Follow this link for more information, https://code.visualstudio.com/docs/python/environments


y
yurisich

If you want to walk up from the current module/file that was handed to pylint looking for the root of the module, this will do it.

[MASTER]
init-hook=sys.path += [os.path.abspath(os.path.join(os.path.sep, *sys.argv[-1].split(os.sep)[:i])) for i, _ in enumerate(sys.argv[-1].split(os.sep)) if os.path.isdir(os.path.abspath(os.path.join(os.path.sep, *sys.argv[-1].split(os.sep)[:i], '.git')))][::-1]

If you have a python module ~/code/mymodule/, with a top-level directory layout like this

~/code/mymodule/
├── .pylintrc
├── mymodule/
│   └── src.py
└── tests/
    └── test_src.py

Then this will add ~/code/mymodule/ to your python path and allow for pylint to run in your IDE, even if you're importing mymodule.src in tests/test_src.py.

You could swap out a check for a .pylintrc instead but a git directory is usually what you want when it comes to the root of a python module.

Before you ask

The answers using import sys, os; sys.path.append(...) are missing something that justifies the format of my answer. I don't normally write code that way, but in this case you're stuck dealing with the limitations of the pylintrc config parser and evaluator. It literally runs exec in the context of the init_hook callback so any attempt to import pathlib, use multi-line statements, store something into variables, etc., won't work.

A less disgusting form of my code might look like this:

import os
import sys

def look_for_git_dirs(filename):
    has_git_dir = []
    filename_parts = filename.split(os.sep)
    for i, _ in enumerate(filename_parts):
        filename_part = os.path.abspath(os.path.join(os.path.sep, *filename_parts[:i]))
        if os.path.isdir(os.path.join(filename_part, '.git')):
            has_git_dir.append(filename_part)
    return has_git_dir[::-1]

# don't use .append() in case there's < 1 or > 1 matches found
sys.path += look_for_git_dirs(sys.argv[-1])

I wish I could have used pathlib.Path(filename).parents it would have made things much easier.


Although not really suggested, it is possible to import using __import__ function which might be handy here
E
EMP

One workaround that I only just discovered is to actually just run PyLint for the entire package, rather than a single file. Somehow, it manages to find imported module then.


Sounds great; how?
@CeesTimmerman Run pylint ... dir from parent folder. This requires __init__.py to be present in each subfolder with .py files.
In many contexts (such as getting syntactical feedback in an editor) this is not useful.
u
user2826500

I had the same problem and since i could not find a answer I hope this can help anyone with a similar problem.

I use flymake with epylint. Basically what i did was add a dired-mode-hook that check if the dired directory is a python package directory. If it is I add it to the PYTHONPATH. In my case I consider a directory to be a python package if it contains a file named "setup.py".

;;;;;;;;;;;;;;;;;
;; PYTHON PATH ;;
;;;;;;;;;;;;;;;;;

(defun python-expand-path ()
  "Append a directory to the PYTHONPATH."
  (interactive
   (let ((string (read-directory-name 
          "Python package directory: " 
          nil 
          'my-history)))
     (setenv "PYTHONPATH" (concat (expand-file-name string)
                  (getenv ":PYTHONPATH"))))))

(defun pythonpath-dired-mode-hook ()
  (let ((setup_py (concat default-directory "setup.py"))
    (directory (expand-file-name default-directory)))
    ;;   (if (file-exists-p setup_py)
    (if (is-python-package-directory directory)
    (let ((pythonpath (concat (getenv "PYTHONPATH") ":" 
                  (expand-file-name directory))))
      (setenv "PYTHONPATH" pythonpath)
      (message (concat "PYTHONPATH=" (getenv "PYTHONPATH")))))))

(defun is-python-package-directory (directory)
  (let ((setup_py (concat directory "setup.py")))
    (file-exists-p setup_py)))

(add-hook 'dired-mode-hook 'pythonpath-dired-mode-hook)

Hope this helps.


c
chuyik

The key is to add your project directory to sys.path without considering about the env variable.

For someone who use VSCode, here's a one-line solution for you if there's a base directory of your project:

[MASTER]
init-hook='base_dir="my_spider"; import sys,os,re; _re=re.search(r".+\/" + base_dir, os.getcwd()); project_dir = _re.group() if _re else os.path.join(os.getcwd(), base_dir); sys.path.append(project_dir)'

Let me explain it a little bit:

re.search(r".+\/" + base_dir, os.getcwd()).group(): find base directory according to the editing file

os.path.join(os.getcwd(), base_dir): add cwd to sys.path to meet command line environment

FYI, here's my .pylintrc:

https://gist.github.com/chuyik/f0ffc41a6948b6c87c7160151ffe8c2f


S
Sk Kamal Hossain

First, go to your VS Code then press "ctrl + shift + p"

Then search settings.json

Then paste the below code inside the settings.jason.I hope the problem will be solved.

{

"python.pythonPath": "venv/bin/python",
"python.linting.pylintPath": "venv/bin/pylint"

}


Y
YU GU

I got this error when trying to submit a PR. What I end up doing is just to add #pylint: disable=E0401 on the same line where "import" happens.

This helps me to pass the auto test.


M
Mario Mikić

Maybe by manually appending the dir inside the PYTHONPATH?

sys.path.append(dirname)

Hmm, but where would you put that code? At the top of each and every file? I suppose it would work, but it's quite a hack just to get PyLint to work.
@Evgeny: See the answer that Brian M. Hunt recently posted.
And adding this at the top of every file doesn't work for some reason - PyLint seems perfectly content to ignore any modifications to sys.path made from within modules it's scanning. I haven't bothered to research why, though...
t
tterry

In case anybody is looking for a way to run pylint as an external tool in PyCharm and have it work with their virtual environments (why I came to this question), here's how I solved it:

In PyCharm > Preferences > Tools > External Tools, Add or Edit an item for pylint. In the Tool Settings of the Edit Tool dialog, set Program to use pylint from the python interpreter directory: $PyInterpreterDirectory$/pylint Set your other parameters in the Parameters field, like: --rcfile=$ProjectFileDir$/pylintrc -r n $FileDir$ Set your working directory to $FileDir$

Now using pylint as an external tool will run pylint on whatever directory you have selected using a common config file and use whatever interpreter is configured for your project (which presumably is your virtualenv interpreter).


M
Mike C

This is an old question but has no accepted answer, so I'll suggest this: change the import statement in two.py to read:

from .. import one

In my current environment (Python 3.6, VSCode using pylint 2.3.1) this clears the flagged statement.


S
Smitty

Mac user: If you're using Anaconda 3 w/ vsCode and have multiple environments, pointing to the following path via settings.json for vsCode works as well:

{
  "python.pythonPath": "/Users/username/opt/anaconda3/bin/python",
  "python.linting.pylintPath": "/Users/username/opt/anaconda3/bin/python"
}

a
atin

If you are using Windows:

get the path of the python.exe inside the virtual environment you just created

it should be like this Z:\YourProjectFolder\Scripts\python.exe

then go to your vscode and edit the user settings.json

add this line: "python.pythonPath": "Z:\\YourProjectFolder\\Scripts\\python.exe"

save it and that should fix the issue

NOTE: the double backslash instead of single when putting it to the json file

{
    "python.pythonPath": "Z:\\YourProjectFolder\\Scripts\\python.exe"
}

t
thoroc

Hello i was able to import the packages from different directory. I just did the following: Note: I am using VScode

Steps to Create a Python Package Working with Python packages is really simple. All you need to do is:

Create a directory and give it your package's name.

Put your classes in it.

Create a __init__.py file in the directory

For example: you have a folder called Framework where you are keeping all the custom classes there and your job is to just create a __init__.py file inside the folder named Framework.

And while importing you need to import in this fashion--->

from Framework import base

so the E0401 error disappears Framework is the folder where you just created __init__.py and base is your custom module which you are required to import into and work upon Hope it helps!!!!


u
user3226845

this all work for me!

.pylintrc

[MASTER]
; init-hook='import sys; sys.path.append("./venv/lib/python3.8/site-packages")'

; or
init-hook='import sys; sys.path.append(f"./venv/lib/python{sys.version[:3]}/site-packages");'

; or
;init-hook='from distutils.sysconfig import get_python_lib; sys.path.append(get_python_lib())'

; or
; init-hook='import site; sys.path.append(site.getsitepackages()[0])'

This does not provide an answer to the question. Once you have sufficient reputation you will be able to comment on any post; instead, provide answers that don't require clarification from the asker. - From Review
V
Vikas Bhutani

if you using vscode,make sure your package directory is out of the _pychache__ directory.


Also with VS code, there seem to be potential issues with dot in folder names: github.com/PyCQA/pylint/issues/2182
M
M. Andrade

If you are using Cython in Linux, I resolved removing module.cpython-XXm-X-linux-gnu.so files in my project target directory.


R
Racing Tadpole

I found this worked nicely in my local .pylintrc file with a pipenv virtual environment:

[MASTER]
init-hook='import site; sys.path += site.getsitepackages()'

See this post for info about site packages.


t
thoroc

just add this code in .vscode/settings.json file

,"python.linting.pylintPath": "venv/bin/pylint"

This will notify the location of pylint(which is an error checker for python)


You should really mention that venv is your local virtual environment directory. You probably want to add ${workspaceFolder} at the start of the path.