virtualenv activation doesn't work

python pip virtualenv

10,333

Solution 1

Forget about virtualenv, use the brand new Pipenv which is recommended by Python.org

Pipenv automatically creates and manages a virtualenv for your projects, as well as adds/removes packages from your Pipfile (more about this below) as you install/uninstall packages.

First install pipenv using:

$ pip install pipenv

Then, for installing project specific packages, first create your project folder and then install all necessary packages for your project like:

$ mkdir myproject
$ cd myproject

# install `requests` library
$ pipenv install requests

# install more libraries required for your project
$ pipenv install mysql-connector
$ pipenv install numpy

This will create two files, namely Pipfile and Pipfile.lock. You can find the list of all installed packages for the current project in the file Pipfile while Pipfile.lock has info on hashes like sha256 for all the installed packages and their dependencies.

Once you're done with the installation of all necessary packages for your project, then do:

$ pipenv shell

which will launch a subshell in virtual environment. (This does the similar job of source /your/virtualenv/activate)

Then you can start coding.. For example, you can first test whether installed packages are working fine by launching a Python shell and import the packages like below:

$ python
>>> import requests
# ....

To exit out of the (virtualenv) shell, simply do:

$ exit

Now, you're out of the virtual environment created by pipenv

Solution 2

When you are within a venv you should use the following to install a package:

py -m pip install mysql-connector==2.1.3

the -m ensures the package is installed into your venv and not into your root python

10,333

enneppi

Data Science Literature Religion

Updated on September 15, 2022

Comments

enneppi over 1 year
I've created a virtual environment with:
```
$ virtualenv my_ven_test
```
then let's activate the environment with:
```
$ source my_ven_test/bin/activate
```
now let's install a package:
```
(my_ven_test) $ pip install mysql-connector==2.1.3
```
This last line does not take effect. In fact if I check:
```
(my_ven_test) $ pip freeze
```
I see no package installed (as well as the my_ven_test/lib/python/site-package directory doesn't contain the mysql-connector package)

Could you guide me in solving this issue?

Some notes:
- python version: 2.7
- virtualenv version: 15.1.0
- jojo over 6 years
  
  this is (my_ven_test) $ pip freeze right?
- sytech over 6 years
  
  Did you move/rename your venv after creating it? If so, this question may shed some light on the issue. May be useful to check that the output of which pip points to the pip executable in the virtualenv directory. If not, you may have issues with your PATH enviroment variable.
- sytech over 6 years
  
  PATH looks OK to me... Is it possible that you installed pip after creating the virtualenv? Check that the pip executable is actually present in the venv's /bin directory. If it's in there, then the output of which pip should be like /home/hadoop/my_ven_test/bin/pip I would recommend, for sanity's sake, trying to create another virtualenv and see if you're still getting the same problem. Keep in mind you don't want to rename/move your venv after creating it.
- Nathan Vērzemnieks over 6 years
  
  Someone suggested looking at the output of which pip, and I don't see that here. After you activate your venv, what do you get from which pip, echo $VIRTUAL_ENV, and pwd?
- enneppi
  
  @AlexanderHuszagh no difference with python -m pip
- phd
  
  mysql-connector doesn't create mysql-connector in site-packages, it creates mysql and mysqlx directories plus _mysql_connector.so and _mysqlxpb.so libraries. Try pip show mysql-connector.
- heemayl
  
  Whats the output of echo $PATH, from virtualenv?
addohm over 6 years

I found this intriguing. Unfortunatly, with any (new or existing) project I get this - pip.exceptions.InstallationError: Command "python setup.py egg_info" failed with error code 1 in /tmp/tmp13ba53__build/mysqlclient/. What paths exactly is this looking for requirements.txt? It says it finds requirements.txt even in a completely empty folder.
kmario23 over 6 years

@Jaberwocky Sure!! try checking it with pipenv lock -r to get a requirements.txt file.
addohm over 6 years

I don't want one. I want to prevent pipenv install from "automatically detecting" one. It's seeing a requirements.txt when run from an empty folder.
kmario23 over 6 years

@Jaberwocky that's strange. Maybe you can report the issue here: github.com/pypa/pipenv/issues