The most reliable way to check for this is to check whether sys.prefix == sys.base_prefix. If they are equal, you are not in a virtual environment; if they are unequal, you are. Inside a virtual environment, sys.prefix points to the virtual environment, and sys.base_prefix is the prefix of the system Python the virtualenv was created … Read more
July 2018 Update Most people should now use pip install setuptools (possibly with sudo). Some may need to (re)install the python-setuptools package via their package manager (apt-get install, yum install, etc.). This issue can be highly dependent on your OS and dev environment. See the legacy/other answers below if the above isn’t working for you. … Read more
I ran the following command and it upgraded from 1.2.3 to 1.4.0 pip install Django –upgrade Shortcut for upgrade: pip install Django -U Note: if the package you are upgrading has any requirements this command will additionally upgrade all the requirements to the latest versions available. In recent versions of pip, you can prevent this … Read more
pip show <package name> will provide the location for Windows and macOS, and I’m guessing any system. 🙂 For example: > pip show cvxopt Name: cvxopt Version: 1.2.0 … Location: /usr/local/lib/python2.7/site-packages
Note: Since a while back, there are binary wheels for Windows in PyPI, so this should no longer be an issue for Windows users. Below are solutions for Linux, Mac users, since lots of them find this post through web searches. Option 1 Install the psycopg2-binary PyPI package instead, it has Python wheels for Linux … Read more
pip is just a PyPI package like any other; you could use it to upgrade itself the same way you would upgrade any package: pip install –upgrade pip On Windows the recommended command is: python -m pip install –upgrade pip
simply run virtualenv -p python3 envname Update after OP’s edit: There was a bug in the OP’s version of virtualenv, as described here. The problem was fixed by running: pip install –upgrade virtualenv
I’ve found this snippet as an alternative solution. It’s a more graceful removal of libraries than remaking the virtualenv: pip freeze | xargs pip uninstall -y In case you have packages installed via VCS, you need to exclude those lines and remove the packages manually (elevated from the comments below): pip freeze | grep -v … Read more
NOTE: For Python 3.3+, see The Aelfinn’s answer below. Use the –python (or short -p) option when creating a virtualenv instance to specify the Python executable you want to use, e.g.: virtualenv –python=”/usr/bin/python2.6″ “/path/to/new/virtualenv/”
This works for everyone: pip install -r /path/to/requirements.txt Explanation: -r, –requirement < filename > Install from the given requirements file. This option can be used multiple times.