Develop Reference

Pipenv script won't run on Windows using Git Bash

I am running Gitbash for windows and have installed pipenv using pip. Yet when I invoke pipenv nothing happens:
Since there isn't a command not found error, I believe the script is recognized it just isn't running properly.
Pipenv is installed globally:
I also can confirm that the Scripts folder is in the file path:
I don't think it is a problem with Gitbash because I can run other pip packages in the same scripts folder:
I'm also able to run python pipenv.exe but not pipenv.exe when in the Scripts folder:

I've struggled with this myself untill just now.
I've got a few suggestions.
SOLUTION 1:
I was calling Poetry to try and make sense of it as well and then I tried calling both applications from Powershell. Both work as inteded.
SOLUTION 2:
Calling python -m pipenv, as sugested in this other Stack Overflow thread, also works as intended. You could alias the command to pipenv in git bash and call it a day too.
Quoting the docs on the -m flag:
When called with -m module-name, the given module is located on the Python module path and executed as a script.
Quoting appdividend.com:
The -m flag in Python searches the sys.path for the named module and executes its contents as the __main__ module.
It goes through whatever path is in which pipenv and executes the module as a script.
SOLUTION 3:
This is how I ended up fixing my Pipenv blunder.
Reinstall Python and all packages to AppData.
MINGW64 was having trouble seeing Pipenv in C:\Program Files. I also noticed that I had some packages in AppData\Roaming as well, so I figured I'd reinstall Python, unticking the Install for all users option (to trigger AppData installation) to see if I could wrangle all packages together.
After that I tried installing Pipenv and succeeded in calling it as expected.
This is all highly anecdotal. I have no idea why MINGW64 failed to call JUST Pipenv and not Poetry, but this is how I've fixed it on my end.

"ModuleNotFoundError: No module named 'kivymd'" in .spec file

I already did pip install kivymd in my Python project. I also had the kivymd directory in my project.
I'm working with a Mac.
I created a spec file called "coinsnack4.spec" including the code below:
from kivymd import hooks_path as kivymd_hooks_path
However, when I try to package my python project with the spec file with the command:
pyinstaller -y --clean --windowed coinsnack4.spec
I got the error below:
File "coinsnack4.spec", line 3, in <module>
from kivymd import hooks_path as kivymd_hooks_path
ModuleNotFoundError: No module named 'kivymd'
I really don't know why this happens because I already pip install kivymd. I don't know what to do next and I would appreciate if anyone could help me with this error.
Thank you very much!

Why are you facing this issue?
The reason behind this is the concept of virtual environments in python. Each virtual environment is independent of the other. You can use different virtual environments, activate and deactivate them as per your project's requirements.
I would suggest you go through this doc once Python venv
As when you do a `pip install <SOME_PACKAGE> from your local terminal, it installs the package from into the default python environment and from the terminal itself (not pycharm terminal) if you try to execute the python program it will work fine but as soon as you switch to pycharm or any other IDE, it has it's own python environment set and that environment is unaware of what happened in the other python environment. So you need to install the pip package here also, in order to execute the same python program.
Solution:-
The first thing I would suggest is to install the package in the virtual environment that the pycharm is using. For that click on the Terminal icon the below bar of your pycharm window. then do run the below command :-
python3 -m pip install kivymd
If this doesn't work, try configuring the python environment in pycharm.
Below is how you can change or update your python interpreter in pycharm: -
Setting an existing Python interpreter
At any time, you can switch your Python interpreter either using the Python Interpreter selector or in the Project Settings/Preferences.
Creating a new Python interpreter
To add a new interpreter to the current project:
If you have a conda environment, follow the below steps: -
Or if you want to setup a new virtual environment, do as below: -

I think you installed pyinstaller not in project's virtualenv, just:
pip install pyinstaller
then problem will be fixed.

Installing custom packages inside a python venv

I need to install some custom python tools into my python virtual environment. I can install them fine globally.
The venv was created by running python3 -m venv env
My files are laid out like this:
tool/
|-setup.py
project/
|-env/
|-|-bin/
I've installed globally by going to tool/ and running python3 setup.py this works great and I can then open a python terminal and type import tool and everything works.
So now I need to use it in the virtual env. First thing I tried was navigating to project/env/bin and running python3 ~//tool/setup.py which didn't throw errors but when I enter a python shell and try import tool I get the error ImportError: No module named 'tool'
Next I tried activating the venv with source evn/bin/activate navigating to tool/ and installing just like I would globally by running python3 setup.py which again throws no errors and gives a success message but doesn't work in a python shell.
My questions are: is this at all the correct way to install something into a venv when not using pip? and if so, what did I break and how can I fix my setup to work?

Install local dist package into virtualenv

I have a pytest test, let's call it test.py. I used to run this test outside of virtualenv; now I'm trying to run it inside a virtualenv sandbox.
The project is structured like this:
~/project/test # where test.py and all virtualenv files live
~/project/mylibrary
test.py imports from mylibrary. In the past, this worked because I have the code in ~/project/mylibrary installed into /usr/lib/python2.7/dist-packages/mylibrary.
I can't run virtualenv with the --system-site-packages flag. I also can't move the code from ~/project/mylibrary into the ~/project/test folder. How can I get access to the code in mylibrary inside my virtualenv?

You don't need to do anything special - as long as you are working inside a virtualenv, python setup.py install will automatically install packages into
$VIRTUAL_ENV/lib/python2.7/site-packages
rather than your system-wide
/usr/lib/python2.7/dist-packages
directory.
In general it's better to use pip install mylibrary/, since this way you can neatly uninstall the package using pip uninstall mylibrary.
If you're installing a working copy of some code that you're developing, it might be a good idea to install it in "editable" mode using pip install -e mylibrary/, which creates a link to your source directory so that your installed module gets updated as you edit the code.

The easiest way would be to add the directory containing the library to your sys.path

Unable to import a module that is definitely installed

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?

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

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.

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.

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.
Open up Terminal
Type open .bash_profile
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/
Save the file, restart the Terminal, and you're done

The Python import mechanism works, really, so, either:
Your PYTHONPATH is wrong,
Your library is not installed where you think it is
You have another library with the same name masking this one

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

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:
Uninstalled keyring:
sudo pip uninstall keyring
I used sudo's -H option and reinstalled keyring:
sudo -H pip install keyring

In PyCharm, I fixed this issue by changing the project interpreter path.
File -> Settings -> Project -> Project Interpreter
File -> Invalidate Caches… may be required afterwards.

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

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

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.

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.

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.

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

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.

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.

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.

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.

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'

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 :
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".
Then, when jupyter was running I've opened a .ipynb file to give commands.
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.
Last with the command !pip3 install sympy (inside jupyter notebook
session) I've solved the problem, here the screen-shot :
Now, with !pip list the package "sympy" is present, and working :

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

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.

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.

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).

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.

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>

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.

For me it was ensuring the version of the module aligned with the version of Python I was using.. I built the image on a box with Python 3.6 and then injected into a Docker image that happened to have 3.7 installed, and then banging my head when Python was telling me the module wasn't installed...
36m for Python 3.6
bsonnumpy.cpython-36m-x86_64-linux-gnu.so
37m for Python 3.7 bsonnumpy.cpython-37m-x86_64-linux-gnu.so

I know this is a super old post but for me, I had an issue with a 32 bit python and 64 bit python installed. Once I uninstalled the 32 bit python, everything worked as it should.

I have solved my issue that same libraries were working fine in one project(A) but importing those same libraries in another project(B) caused error. I am using Pycharm as IDE at Windows OS.
So, after trying many potential solutions and failing to solve the issue, I did these two things (deleted "Venv" folder, and reconfigured interpreter):
1-In project(B), there was a folder named("venv"), located in External Libraries/. I deleted that folder.
2-Step 1 (deleting "venv" folder) causes error in Python Interpreter Configuration, and
there is a message shown at top of screen saying "Invalid python interpreter selected
for the project" and "configure python interpreter", select that link and it opens a
new window. There in "Project Interpreter" drop-down list, there is a Red colored line
showing previous invalid interpreter. Now, Open this list and select the Python
Interpreter(in my case, it is Python 3.7). Press "Apply" and "OK" at the bottom and you
are good to go.
Note: It was potentially the issue where Virtual Environment of my Project(B) was not recognizing the already installed and working libraries.