Unable to import a module that is definitely installed

Question

After installing mechanize, I don't seem to be able to import it.

I have tried installing from pip, easy_install, and via python setup.py install from this repo: https://github.com/abielr/mechanize. All of this to no avail, as each time I enter my Python interactive I get:

Python 2.7.3 (default, Aug  1 2012, 05:14:39) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import mechanize
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named mechanize
>>> 

The installations I ran previously reported that they had completed successfully, so I expect the import to work. What could be causing this error?

Answer 1

In my case, it is permission problem. The package was somehow installed with root rw permission only, other user just cannot rw to it!

Answer 2

I had the same problem: script with import colorama was throwing an ImportError, but sudo pip install colorama was telling me "package already installed".

My fix: run pip without sudo: pip install colorama. Then pip agreed it needed to be installed, installed it, and my script ran. Or even better, use python -m pip install <package>. The benefit of this is, since you are executing the specific version of python that you want the package in, pip will unequivocally install the package into the "right" python. Again, don't use sudo in this case... then you get the package in the right place, but possibly with (unwanted) root permissions.

My environment is Ubuntu 14.04 32-bit; I think I saw this before and after I activated my virtualenv.

Answer 3

I was able to correct this issue with a combined approach. First, I followed Chris' advice, opened a command line and typed 'pip show packagename' This provided the location of the installed package.

Next, I opened python and typed 'import sys', then 'sys.path' to show where my python searches for any packages I import. Alas, the location shown in the first step was NOT in the list.

Final step, I typed 'sys.path.append('package_location_seen_in_step_1'). You optionally can repeat step two to see the location is now in the list.

Test step, try to import the package again... it works.

The downside? It is temporary, and you need to add it to the list each time.

Answer 4

It's the python path problem.

In my case, I have python installed in:

/Library/Frameworks/Python.framework/Versions/2.6/bin/python,

and there is no site-packages directory within the python2.6.

The package(SOAPpy) I installed by pip is located

/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/

And site-package is not in the python path, all I did is add site-packages to PYTHONPATH permanently.

1. Open up Terminal

2. Type open .bash_profile

3. In the text file that pops up, add this line at the end:

   export PYTHONPATH=$PYTHONPATH:/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/
   

4. Save the file, restart the Terminal, and you're done

Answer 5

The Python import mechanism works, really, so, either:

1. Your PYTHONPATH is wrong,
2. Your library is not installed where you think it is
3. You have another library with the same name masking this one

Answer 6

I have been banging my head against my monitor on this until a young-hip intern told me the secret is to "python setup.py install" inside the module directory.

For some reason, running the setup from there makes it just work.

To be clear, if your module's name is "foo":

[burnc7 (2016-06-21 15:28:49) git]# ls -l
total 1
drwxr-xr-x 7 root root  118 Jun 21 15:22 foo
[burnc7 (2016-06-21 15:28:51) git]# cd foo
[burnc7 (2016-06-21 15:28:53) foo]# ls -l
total 2
drwxr-xr-x 2 root root   93 Jun 21 15:23 foo
-rw-r--r-- 1 root root  416 May 31 12:26 setup.py
[burnc7 (2016-06-21 15:28:54) foo]# python setup.py install
<--snip-->

If you try to run setup.py from any other directory by calling out its path, you end up with a borked install.

DOES NOT WORK:

python /root/foo/setup.py install

DOES WORK:

cd /root/foo
python setup.py install

Answer 7

I encountered this while trying to use keyring which I installed via sudo pip install keyring. As mentioned in the other answers, it's a permissions issue in my case.

What worked for me:

1. Uninstalled keyring:

• sudo pip uninstall keyring

2. I used sudo's -H option and reinstalled keyring:

• sudo -H pip install keyring

Answer 8

In PyCharm, I fixed this issue by changing the project interpreter path.

File -> Settings -> Project -> Project Interpreter

File -> Invalidate Caches… may be required afterwards.

Answer 9

Check that you are using the same python version in the interpreter of your IDE or code editor and on your system. For example, check your python version in the terminal with python3 --version And check python version for interpreter in VSCode by cmd+shift+p-> Python: Select interpreter -> select the same version as you see in your terminal.

Answer 10

I couldn't get my PYTHONPATH to work properly. I realized adding export fixed the issue:

(did work)

export PYTHONPATH=$PYTHONPATH:~/test/site-packages

vs.

(did not work)

PYTHONPATH=$PYTHONPATH:~/test/site-packages

Answer 11

This problem can also occur with a relocated virtual environment (venv).

I had a project with a venv set up inside the root directory. Later I created a new user and decided to move the project to this user. Instead of moving only the source files and installing the dependencies freshly, I moved the entire project along with the venv folder to the new user.

After that, the dependencies that I installed were getting added to the global site-packages folder instead of the one inside the venv, so the code running inside this env was not able to access those dependencies.

To solve this problem, just remove the venv folder and recreate it again, like so:

$ deactivate
$ rm -rf venv
$ python3 -m venv venv
$ source venv/bin/activate
$ pip install -r requirements.txt

Answer 12

Something that worked for me was:

python -m pip install -user {package name}

The command does not require sudo. This was tested on OSX Mojave.

Answer 13

In my case I had run pip install Django==1.11 and it would not import from the python interpreter.

Browsing through pip's commands I found pip show which looked like this:

> pip show Django
Name: Django
Version: 1.11
...
Location: /usr/lib/python3.4/site-packages
...

Notice the location says '3.4'. I found that the python-command was linked to python2.7

/usr/bin> ls -l python
lrwxrwxrwx 1 root root 9 Mar 14 15:48 python -> python2.7

Right next to that I found a link called python3 so I used that. You could also change the link to python3.4. That would fix it, too.

Answer 14

I had colorama installed via pip and I was getting "ImportError: No module named colorama"

So I searched with "find", found the absolute path and added it in the script like this:

import sys
sys.path.append("/usr/local/lib/python3.8/dist-packages/")
import colorama 

And it worked.

Answer 15

I had just the same problem, and updating setuptools helped:

python3 -m pip install --upgrade pip setuptools wheel

After that, reinstall the package, and it should work fine :)

The thing is, the package is built incorrectly if setuptools is old.

Answer 16

In my case it was a problem with a missing __init__.py file in the module, that I wanted to import in a Python 2.7 environment.

Python 3.3+ has Implicit Namespace Packages that allow it to create a packages without an __init__.py file.

Answer 17

Had this problem too. The package was installed on Python 3.8.0 but VS Code was running my script using an older version (3.4)

fix in terminal:

py <yourfile>.py

Make sure you're installing the package on the right Python version.

Answer 18

If the other answers mentioned do not work for you, try deleting your pip cache and reinstalling the package. My machine runs Ubuntu14.04 and it was located under ~/.cache/pip. Deleting this folder did the trick for me.

Answer 19

Also, make sure that you do not confuse pip3 with pip. What I found was that package installed with pip was not working with python3 and vice-versa.

Answer 20

I had similar problem (on Windows) and the root cause in my case was ANTIVIRUS software! It has "Auto-Containment" feature, that wraps running process with some kind of a virtual machine. Symptoms are: pip install somemodule works fine in one cmd-line window and import somemodule fails when executed from another process with the error

ModuleNotFoundError: No module named 'somemodule'

Answer 21

In my case (an Ubuntu 20.04 VM on WIN10 Host), I have a disordered situation with many version of Python installed and variuos point of Shared Library (installed with pip in many points of the File System). I'm referring to 3.8.10 Python version. After many tests, I've found a suggestion searching with google (but' I'm sorry, I haven't the link). This is what I've done to resolve the problem :

1. From shell session on Ubuntu 20.04 VM, (inside the Home, in my case /home/hduser), I've started a Jupyter Notebook session with the command "jupyter notebook".

2. Then, when jupyter was running I've opened a .ipynb file to give commands.

3. First : pip list --> give me the list of packages installed, and, sympy wasn't present (although I had installed it with "sudo pip install sympy" command.

4. Last with the command !pip3 install sympy (inside jupyter notebook session) I've solved the problem, here the screen-shot :

5. Now, with !pip list the package "sympy" is present, and working :

Answer 22

In my case, I assumed a package was installed because it showed up in the output of pip freeze. However, just the site-packages/*.dist-info folder is enough for pip to list it as installed despite missing the actual package contents (perhaps from an accidental deletion). This happens even when all the path settings are correct, and if you try pip install <pkg> it will say "requirement already satisfied".

The solution is to manually remove the dist-info folder so that pip realizes the package contents are missing. Then, doing a fresh install should re-populate anything that was accidentally removed

Answer 23

Not sure if this will help anyone, but I had a similar issue on Mac M1 with zsh. Turns out I had set an alias command in my .zshrc file with the same name as my python command (python3).

To solve the issue, I just had to unalias the command. I ran:

unalias python3

both from my home terminal and from the terminal in Visual Studio.

Answer 24

I solved it by calling the following command on the terminal

eval "$(conda shell.bash hook)"

Answer 25

When you install via easy_install or pip, is it completing successfully? What is the full output? Which python installation are you using? You may need to use sudo before your installation command, if you are installing modules to a system directory (if you are using the system python installation, perhaps). There's not a lot of useful information in your question to go off of, but some tools that will probably help include:

• echo $PYTHONPATH and/or echo $PATH: when importing modules, Python searches one of these environment variables (lists of directories, : delimited) for the module you want. Importing problems are often due to the right directory being absent from these lists

• which python, which pip, or which easy_install: these will tell you the location of each executable. It may help to know.

• Use virtualenv, like @JesseBriggs suggests. It works very well with pip to help you isolate and manage the modules and environment for separate Python projects.

Answer 26

I had this exact problem, but none of the answers above worked. It drove me crazy until I noticed that sys.path was different after I had imported from the parent project. It turned out that I had used importlib to write a little function in order to import a file not in the project hierarchy. Bad idea: I forgot that I had done this. Even worse, the import process mucked with the sys.path--and left it that way. Very bad idea.

The solution was to stop that, and simply put the file I needed to import into the project. Another approach would have been to put the file into its own project, as it needs to be rebuilt from time to time, and the rebuild may or may not coincide with the rebuild of the main project.

Answer 27

I had this problem with 2.7 and 3.5 installed on my system trying to test a telegram bot with Python-Telegram-Bot.

I couldn't get it to work after installing with pip and pip3, with sudo or without. I always got:

Traceback (most recent call last):
  File "telegram.py", line 2, in <module>
    from telegram.ext import Updater
  File "$USER/telegram.py", line 2, in <module>
    from telegram.ext import Updater
ImportError: No module named 'telegram.ext'; 'telegram' is not a package

Reading the error message correctly tells me that python is looking in the current directory for a telegram.py. And right, I had a script lying there called telegram.py and this was loaded by python when I called import.

Conclusion, make sure you don't have any package.py in your current working dir when trying to import. (And read error message thoroughly).

Answer 28

I had a similar problem using Django. In my case, I could import the module from the Django shell, but not from a .py which imported the module.
The problem was that I was running the Django server (therefore, executing the .py) from a different virtualenv from which the module had been installed.

Instead, the shell instance was being run in the correct virtualenv. Hence, why it worked.

Answer 29

This Works!!!

This often happens when module is installed to an older version of python or another directory, no worries as solution is simple. - import module from directory in which module is installed. You can do this by first importing the python sys module then importing from the path in which the module is installed

import sys
sys.path.append("directory in which module is installed")

import <module_name>

Answer 30

Most of the possible cases have been already covered in solutions, just sharing my case, it happened to me that I installed a package in one environment (e.g. X) and I was importing the package in another environment (e.g. Y). So, always make sure that you're importing the package from the environment in which you installed the package.