Based on your comments to orip's post, I guess this is what happened:

1. You edited __init__.py on windows.
2. The windows editor added something non-printing, perhaps a carriage-return (end-of-line in Windows is CR/LF; in unix it is LF only), or perhaps a CTRL-Z (windows end-of-file).
3. You used WinSCP to copy the file to your unix box.
4. WinSCP thought: "This has something that's not basic text; I'll put a .bin extension to indicate binary data."
5. The missing __init__.py (now called __init__.py.bin) means python doesn't understand toolkit as a package.
6. You create __init__.py in the appropriate directory and everything works... ?

Does

(local directory)/site-packages/toolkit

have a __init__.py?

To make import walk through your directories every directory must have a __init__.py file.

You are reading this answer says that your __init__.py is in the right place, you have installed all the dependencies and you are still getting the ImportError.

I was facing a similar issue except that my program would run fine when ran using PyCharm but the above error when I would run it from the terminal. After digging further, I found out that PYTHONPATH didn't have the entry for the project directory. So, I set PYTHONPATH per Import statement works on PyCharm but not from terminal:

export PYTHONPATH=$PYTHONPATH:`pwd`  (OR your project root directory)

There's another way to do this using sys.path as:

import sys
sys.path.insert(0,'<project directory>') OR
sys.path.append('<project directory>')

You can use insert/append based on the order in which you want your project to be searched.

For me, it was something really stupid. I installed the library using pip3 install but was running my program as python program.py as opposed to python3 program.py.

I solved my own problem, and I will write a summary of the things that were wrong and the solution:

The file needs to be called exactly __init__.py. If the extension is different such as in my case .py.bin then Python cannot move through the directories and then it cannot find the modules. To edit the files you need to use a Linux editor, such as vi or nano. If you use a Windows editor this will write some hidden characters.

Another problem that was affecting it was that I had another Python version installed by the root, so if someone is working with a local installation of python, be sure that the Python installation that is running the programs is the local Python. To check this, just do which python, and see if the executable is the one that is in your local directory. If not, change the path, but be sure that the local Python directory is before than the other Python.

To mark a directory as a package you need a file named __init__.py, does this help?

To all those who still have this issue. I believe Pycharm gets confused with imports. For me, when i write 'from namespace import something', the previous line gets underlined in red, signaling that there is an error, but works. However ''from .namespace import something' doesn't get underlined, but also doesn't work.

Try

try:
    from namespace import something 
except NameError:
    from .namespace import something

Yup. You need the directory to contain the __init__.py file, which is the file that initializes the package. Here, have a look at this.

The __init__.py files are required to make Python treat the directories as containing packages; this is done to prevent directories with a common name, such as string, from unintentionally hiding valid modules that occur later on the module search path. In the simplest case, __init__.py can just be an empty file, but it can also execute initialization code for the package or set the __all__ variable, described later.

In my case, because I'm using PyCharm and PyCharm create a 'venv' for every project in project folder, but it is only a mini env of python. Although you have installed the libraries you need in Python, but in your custom project 'venv', it is not available. This is the real reason of 'ImportError: No module named xxxxxx' occurred in PyCharm. To resolve this issue, you must add libraries to your project custom env by these steps:

• In PyCharm, from menu 'File'->Settings
• In Settings dialog, Project: XXXProject->Project Interpreter
• Click "Add" button, it will show you 'Available Packages' dialog
• Search your library, click 'Install Package'
• Then, all you needed package will be installed in you project custom 'venv' folder.

Enjoy.

If you are using a setup script/utility (e.g. setuptools) to deploy your package, don't forget to add the respective files/modules to the installer.

When supported, use find_packages() or similar to automatically add new packages to the setup script. This will absolutely save you from a headache, especially if you put your project aside for some time and then add something later on.

import setuptools

setuptools.setup(
    name="example-pkg",
    version="0.0.1",
    author="Example Author",
    author_email="author@example.com",
    description="A small example package",
    packages=setuptools.find_packages(),
    classifiers=[
        "Programming Language :: Python :: 3",
        "Operating System :: OS Independent",
    ],
    python_requires='>=3.6',
)

(Example taken from setuptools documentation)

I had the same problem (Python 2.7 Linux), I have found the solution and i would like to share it. In my case i had the structure below:

Booklet
-> __init__.py
-> Booklet.py
-> Question.py
default
-> __init_.py
-> main.py

In 'main.py' I had tried unsuccessfully all the combinations bellow:

from Booklet import Question
from Question import Question
from Booklet.Question import Question
from Booklet.Question import *
import Booklet.Question
# and many othet various combinations ...

The solution was much more simple than I thought. I renamed the folder "Booklet" into "booklet" and that's it. Now Python can import the class Question normally by using in 'main.py' the code:

from booklet.Booklet import Booklet
from booklet.Question import Question
from booklet.Question import AnotherClass

From this I can conclude that Package-Names (folders) like 'booklet' must start from lower-case, else Python confuses it with Class names and Filenames.

Apparently, this was not your problem, but John Fouhy's answer is very good and this thread has almost anything that can cause this issue. So, this is one more thing and I hope that maybe this could help others.

In linux server try dos2unix script_name

(remove all (if there is any) pyc files with command find . -name '*.pyc' -delete)

and re run in the case if you worked on script on windows

In my case, I was using sys.path.insert() to import a local module and was getting module not found from a different library. I had to put sys.path.insert() below the imports that reported module not found. I guess the best practice is to put sys.path.insert() at the bottom of your imports.

I've found that changing the name (via GUI) of aliased folders (Mac) can cause issues with loading modules. If the original folder name is changed, remake the symbolic link. I'm unsure how prevalent this behavior may be, but it was frustrating to debug.

For me, running the file as a module helped.

Instead of

python myapp/app.py

using

python -m myapp.app

It's not exactly the same but it might be a better approach in some cases.

another cause makes this issue

file.py

#!/bin/python
from bs4 import BeautifulSoup

• if your default python is pyyhon2

$ file $(which python)
/sbin/python: symbolic link to python2

• file.py need python3, for this case(bs4)
• you can not execute this module with python2 like this:

$ python file.py
# or
$ file.py
# or
$ file.py # if locate in $PATH

• Tow way to fix this error,

# should be to make python3 as default by symlink
$ rm $(which python) && ln -s $(which python3) /usr/bin/python
# or use alias
alias python='/usr/bin.../python3'

or change shebang in file.py to

#!/usr/bin/...python3

In my case I was including the path to package.egg folder rather than the actual package underneath. I copied the package to top level and it worked.

This worked for me: Created __init__.py file inside parent folder (in your case, inside site-packages folder). And imported like this:

from site-packages.toolkit.interface import interface

Hope it will be useful for you as well !

I have a similar problem. I created a new virtual environment named python3.6.

conda create -n python3.6 python=3.6
pip install pandas

everything is ok, but when I run script, a error occurred

ModuleNotFoundError: No module named 'pandas'

I found that the metadata of the Python package and cache of pip has been updated, but it does not actually download the pandas package. so I try reinstall by pip,

pip uninstall pandas --no-cache-dir
pip install pandas 

This solved it.

In the ubuntu apt-get installer, the python3 versions of packages are usually named

python3-XYZ

and the python2 versions

python-XYZ

As a rule of thumb, try python3-XYZ or python-XYZ of the package that is mentioned in the error message. And just guessing is not needed, search through the apt cache with a RegEx. Then:

$ apt-cache search "python.*toolkit.*interface"
python3-cli-helpers - easy command-line apps with Python
python3-exam - Python module to help write better tests
python3-fltk - Python wrapper for the Fast Light Toolkit
python3-mpltoolkits.basemap - matplotlib toolkit to plot on map projections (Python 3)
python3-nltk - Python3 libraries for natural language processing
python3-onnx - Open Neural Network Exchange (ONNX) (Python)
python3-paraview - Parallel Visualization Application. python-support
python3-pyswarms - research toolkit for particle swarm optimization in Python
python3-wxgtk-media4.0 - Python 3 interface to the wxWidgets Cross-platform C++ GUI toolkit (wx.media)
python3-wxgtk-webview4.0 - Python 3 interface to the wxWidgets Cross-platform C++ GUI toolkit (wx.html2)
python3-wxgtk4.0 - Python 3 interface to the wxWidgets Cross-platform C++ GUI toolkit
python3-xapian - Xapian search engine interface for Python3
wxglade - GUI designer written in Python with wxPython

It does not find it.

Mind that this apt-get trick will sometimes be needed for dependent packages as well or instead.

I had the same error message for the flask package for python2.7 and it vanished when I tried:

sudo apt-get install python-flask

Thus, try:

sudo apt-get install python-[YOURPYTHONVERION]-[YOURERRORPACKAGE]

or check mentioned dependencies.

Using sys.path.append worked for me, as mentioned in an answer already. At first I thought it was not working until I realized I had a space before the directory path. So be sure you have no typos or spaces before you path(s)

The file encoding of all your python files must be utf-8.

See here: https://github.com/jupyter/notebook/issues/3166#issuecomment-581332097

If you're on a tight deadline and all else fails:

import sys
import os
wd = '/path/to/current/script/'
sys.path.append(wd)
os.chdir(wd)
print(os.getcwd())
print(sys.path)