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virtualenv: command not found in Python

I am trying to create a new virtual environment for a tutorial. I have installed virtualenv and virtualenvwrapper multiple times but every time I try creating a new virtual environment my terminal displays - mkvirtualenv: command not found. When I try finding out the version of virtualenv it shows virtualenv: command not found. Something similar was happening with my pip installation as well but then it got resolved when I used some command.
I would like to point out that my PATH seems to be really messed up. The PATH is pointing to /Library/Frameworks/Python.framework/Versions/3.8/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Library/Apple/usr/bin. Please help.
I saw something else when I use pip show virtualenv it gives me details of the version and the author but when I use virtualenv --version it sends a virtualenv: command not found.

First of all, you will need to install virtualenv as it is a python 2 external dependency.
pip install virtualenv
this will allow you to use virtualenv globally.
Alternatively, you can use from Python 3.5+
python -m virtualenv venv
However if you dont wish to support python 2 you can use venv which is installed on from python 3.3
python3 -v venv venv

Took quite some time to figure it out but what worked for me was to install it using pip3 install instead of pip install
pip3 install virtualenv

How to install a Python package inside a virtual environment with Pip (OS X)

Edit:
I'm going to close this question as the reason its happening is different from my original assumption, and it's clearer to ask the question anew:
Pip installs packages in the wrong directory with virtualenv
The accepted answer doesn't directly answer the original question, but is a very useful overview.
Based on discussion below the issue is that even after
$ source ~/PycharmProjects/Practice/venv/bin/activate
$ pip install numpy
numpy is installed in /usr/local/lib/python2.7/site-packages
What could the reason for this be?
Original:
Using Python on OS X via Homebrew:
I've been trying much of the day to sort this out but either I get a must supply either home or prefix/exec-prefix -- not both error, or the package I try to install goes into totally the wrong place:
$ pip3 --version
pip 18.1 from /usr/local/lib/python3.7/site-packages/pip (python 3.7)
$ cd venv
$ pip3 install numpy
..... [snip with following error:]
"must supply either home or prefix/exec-prefix -- not both")
Using this hint
$ pip3 install numpy -t .
Then I get a new error,
`Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/.../pip-install-0fvveq3v/package/'
Searching around SO gives various possibilities involving pip install setuptools. but pip install throws the above error or installs in the wrong place. i.e. the solution involves something that's causing the error in the first place.
I tried to use the Python.org installer but it didn't install pip at all. (The custom installer showed the option checked but with size zero).

An introductory overview is available in this nice tutorial. Here is a good summary with more detail. But, if you renamed or moved the virtual env dir after its creation, it could break it. Create a new one from scratch: $ cd ~/PycharmProjects; python3 -mvenv newenv ; Activate: $ source newenv/bin/activate ; Install something: $ pip install colorama (same as pip3 install only if venv activated); Check: ls ~/PycharmProjects/newenv/lib/python3*/site-packages ; Deactivate: $ deactivate
Then you could try this solution for Pycharm: how to associate a virtual environment with a python project in pycharm. PyCharm indeed comes bundled with virtualenv which could have been customized, please look into Pycharm-specific resources: creating virtual environments and installing packages in Pycharm.
If you have installed PyPI's mainstream virtualenv, by default it will create new environments with the python interpreter that virtualenv was installed with. But it's possible to specify an alternate Python Interpreter upon a new env creation: $ virtualenv -p python3.7 newenvname
Regarding the error DistutilsOptionError: must supply either home or prefix - please check this and this for solutions. Homebrew'ed mappings between python and pip are described here. The normal pip install --user is disabled in homebrewed Python, but there are workarounds. MacOS system Python doesn't provide pip, but it can installed, reinstalled or upgraded for any specific python version manually. Original non-brewed installers are also available for all Python versions: https://www.python.org/downloads/mac-osx/
By default there's no pip.conf, but it can be created by hand to customize things. All possible pip.conf locations (per-user, per-venv, and global/system-wide, and how they override each other) are listed here. If someone faces an issue, they could use pip config list command to see their active configuration, or locate pip.conf and find it.
Finally, you may want to ensure you aren't using pip against macOS' system python. Shell commands such as $ brew info python, which pip, which pip3, pip3 -V, which python3 can help you see what you actually use. Since the macOS default $PATH used to be /usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin, stock macOS binaries (including python) may take precedence over some homebrew'ed installations (including python). If so, a custom PATH could be exported via the ~/.bashrc if required.

Paths for pip and python out of sync?

I have an application that is using the requests module. I have installed this module but when I try to run my app it throws the error:
import requests
ImportError: No module named requests
When I run pip list i see an entry for requests:
...
pytz (2017.2)
requests (2.18.4)
scipy (0.19.1)
...
so I know it's installed.
I confirmed that both pip and python are version 2.7:
➜ pip --version
pip 9.0.1 from /usr/local/lib/python2.7/site-packages (python 2.7)
➜ python --version
Python 2.7.10
When I look at the paths for pip and python they look to be different:
➜ which pip
/usr/local/bin/pip
➜ which python
/usr/bin/python
Am I correct in suspecting that these mismatched paths are the cause of my problem?
What would cause this to happen? I had assumed that as long as both pip/python were 2.7 they would be working together well.
How can I fix this problem?
This seems like something that would have already been solved, but after googling and going over the suggested questions when creating this post I haven't come across a post that has a clear solution that goes over both how this could happen and how to fix it.

I would suggest trying some of these options:
1) Make sure that you have an environment variable pointing to where the current pip directory is.
2) Move the pip folder to the directory that your other python packages are in.
3) Uninstall and then reinstall pip (to a different location on your path).
4) Uninstall python and then reinstall python. I would suggest installing it through conda or miniconda to make sure that you have everything downloaded to the same place. Miniconda will by default store pip with all of the other packages and should run cleanly.

How to install packages in different version of python?

I have a MacBook Pro that came pre-installed with python2.7. I later installed python3 and ipython notebook. I installed pip too to install packages, and am able to install packages and run program from python3. However, for another project I need to run code in python2.7, and I am not sure how to install it in python2.7 folder.
I tried using pip for installing packages to 2.7, but it kept giving error saying package already exists. When I check for version of python using --version, I see 2 pythons installed. However, when I check for pip and pip3, both seem to be in th same folder.
Any tips on how to install packages in python2.7, without making any changes to 3.3? I am using python3 and ipython notebooks for another project.
viveks-mbp:~ vivekyadav$ which pip
/Library/Frameworks/Python.framework/Versions/3.3/bin/pip
viveks-mbp:~ vivekyadav$ which pip3
/Library/Frameworks/Python.framework/Versions/3.3/bin/pip3
viveks-mbp:~ vivekyadav$ which python
/usr/bin/python
viveks-mbp:~ vivekyadav$ which python3
/Library/Frameworks/Python.framework/Versions/3.3/bin/python3

You can use the virtualenv to create a kind of sandbox.
$ virtualenv <work-directory>
$ source <work-directory>/bin/activate
The last command initiate your virtual environment, totally isolated from the system. So every pip command will install the package inside this directory.
But you have to run your application inside the virtual environment too.

virtualenv does not include pip

I am trying to create a virtual environment using virtualenv on Mac OS X El Capitan. I have installed Python 2.7.11 with brew, which includes pip, wheel and setuptools by default.
Hovewer, when I try to install virtualenv following instructions in the documentation or from any other resource, I get several problems:
virtualenv executable is not placed in /usr/local/bin after pip makes its job, so I need to ln -s it by hand (it may indicate, that there is something wrong with installation on this step).
After I run virtualenv venv, it creates new environment, catches Python 2.7.11 from brew-installation, but: there is no pip inside bin folder. That means, that if I try which pip, having venv activated, it returns a global position of pip — /usr/local/bin/pip, not /path/to/venv/bin/pip.
As a consequence, installing packages inside venv uses global pip and installs them to a global sites-packages, not that inside venv, and it's quite the opposite of what environment should do.
Could you please suggest what may be wrong and how to fix it?
EDIT: The thing to mention is that I used to have other versions of Python installed on my computer, which I have recently deleted as it is described in this answer. Maybe it causes the issue, and some more thorough cleaning is needed.

Try removing or renaming the .pydistutils.cfg file in your home directory, e.g. by renaming with mv ~/.pydistutils.cfg ~/oldpydistutils.cfg
I'm putting a detailed answer here to help others, but the original credit goes to this answer. If you know what specifically in .pydistutils.cfg was causing the problem, let me know!
I was having the same issue: my virtual environments were created without a local copy of pip, although they had a local copy of python. This meant that using $ pip from within the virtual environment installed to the global package location, and was not visible to the environment's python.
How I diagnosed this on my machine:
I create a virtualenvironment with $ virtualenv env
Activated the virtual environment with $ source env/bin/activate
Checked python location: run (env)$ which python with output /Users/<username>/env/bin/python (as expected)
Checked pip location: run (env)$ which pip with output /usr/local/bin/pip (NOT expected)
To check where our packages are going, we can try to install a package in the virtual environment:
Try to install a package: (env)$ pip install HTTPServer which succeeds
Try to run the package: (env)$ python -m HTTPServer which fails with error /Users/emunsing/env/bin/python: No module named HTTPServer
To double-check, try to install again: (env)$ pip install HTTPServer which produces Requirement already satisfied (use --upgrade to upgrade): HTTPServer in /usr/local/lib/python2.7/site-packages
Double-checking, we see that there's no Pip in the environment's /bin folder:
$ ls env/bin
activate activate.fish python python2
activate.csh activate_this.py python-config python2.7
And so while the system finds the local python version, it can't find a local pip to use and traverses the $PATH. It ended up using pip from /usr/local/bin, leaving me unable to install packages locally to the virtual environment.
Here's what I tried:
- Reinstalling python brew uninstall python followed by brew upgrade and brew install python --build-from-source
- Installing pip using the get-pip.py command as described in the Pip documentation
Here's what I ruled out:
- I was not using sudo pip ... which caused similar problems in this other question and haven't done so at any time on this Python/pip install
- My virtual environment didn't show a local installation of pip, as was the case in these similar questions: This one for Windows, This one for Mac OS X.
Ultimately, I found that eliminating the ~/.pydistutils.cfg file fixed the problem, allowing for fresh virtual environments that had their own local pip. The contents of my ~/.pydistutils.cfg file were:
[global]
verbose=1
[install]
install-scripts=$HOME/bin
[easy_install]
install-scripts=$HOME/bin
Simply renaming the ~/.pydistutils.cfg file appears to fix the problem: it seems that although this file was created by the homebrew installation, some settings in this file may be incompatible with virtualenv. While removing this file hasn't had any bad effects on my system, you may need to use the --user flag when installing packages with pip to the global environment (e.g. $ pip install --user HTTPServer). Here are more details on .pydistutils.cfg if you want to work on tailoring it for your needs.

virtualenv executable is not placed in /usr/local/bin after pip makes its job, so I need to ln -s it by hand (it may indicate, that there is something wrong with installation on this step).
Don't do that. That will only hide the bug and not solve the problem. Here's a short guide how to debug this kind of issues:
Start with which -a python. The first path you see should be /usr/local/bin/python, if not check your PATH variable.
Next, check which -a pip. Again the first path should be /usr/local/bin/pip. If not, run python -m ensurepip and recheck.
Now install virtualenv using pip install virtualenv, after that check the output of which -a virtualenv. The first path should be /usr/local/bin/virtualenv, if not check the output of env |grep PYTHON for unexpected environment variables.
Finally check the output of virtualenv --version to make sure you have the latest version.

I had the issue when running virtualenv: "ImportError: No module named pip."
My solution was to downgrade virtualenv. I had 16.2.0.
pip uninstall virtualenv
pip install virtualenv==15.1.0

Just hit same issue on Linux. Seems like there are multiple causes of this issue, but for me answer was to remove ~/.pip/.
Details: I had this in my .pip/pip.conf for some reason I can't remember:
$ cat ~/.pip/pip.conf
[global]
use_https = True
index = https://pypi.python.org/pypi
prefix = /home/sam/local/
and was using local versions on Python, Pip installed at ~/local/. For some reason virtualenv installed pip must pick up prefix = /home/sam/local/ setting and pip was being installed there.

Try this: sudo apt install pythonV.v-distutils.
In my case V.v == 3.8.
This worked for me.