What's the proper way to install pip, virtualenv, and distribute for Python?

Question

You can do this without installing anything into python itself.

You don't need sudo or any privileges.

You don't need to edit any files.

Install virtualenv into a bootstrap virtual environment. Use the that virtual environment to create more. Since virtualenv ships with pip and distribute, you get everything from one install.

1. Download virtualenv:
   • http://pypi.python.org/pypi/virtualenv
   • https://pypi.python.org/packages/source/v/virtualenv/virtualenv-12.0.7.tar.gz (or whatever is the latest version!)
2. Unpack the source tarball
3. Use the unpacked tarball to create a clean virtual environment. This virtual environment will be used to "bootstrap" others. All of your virtual environments will automatically contain pip and distribute.
4. Using pip, install virtualenv into that bootstrap environment.
5. Use that bootstrap environment to create more!

Here is an example in bash:

# Select current version of virtualenv:
VERSION=12.0.7
# Name your first "bootstrap" environment:
INITIAL_ENV=bootstrap
# Set to whatever python interpreter you want for your first environment:
PYTHON=$(which python)
URL_BASE=https://pypi.python.org/packages/source/v/virtualenv

# --- Real work starts here ---
curl -O $URL_BASE/virtualenv-$VERSION.tar.gz
tar xzf virtualenv-$VERSION.tar.gz
# Create the first "bootstrap" environment.
$PYTHON virtualenv-$VERSION/virtualenv.py $INITIAL_ENV
# Don't need this anymore.
rm -rf virtualenv-$VERSION
# Install virtualenv into the environment.
$INITIAL_ENV/bin/pip install virtualenv-$VERSION.tar.gz

Now you can use your "bootstrap" environment to create more:

# Create a second environment from the first:
$INITIAL_ENV/bin/virtualenv py-env1
# Create more:
$INITIAL_ENV/bin/virtualenv py-env2

Go nuts!

Note

This assumes you are not using a really old version of virtualenv. Old versions required the flags --no-site-packges (and depending on the version of Python, --distribute). Now you can create your bootstrap environment with just python virtualenv.py path-to-bootstrap or python3 virtualenv.py path-to-bootstrap.

I think Glyph means do something like this:

1. Create a directory ~/.local, if it doesn't already exist.
2. In your ~/.bashrc, ensure that ~/.local/bin is on PATH and that ~/.local is on PYTHONPATH.

3. Create a file ~/.pydistutils.cfg which contains

   [install]
   prefix=~/.local
   

   It's a standard ConfigParser-format file.

4. Download distribute_setup.py and run python distribute_setup.py (no sudo). If it complains about a non-existing site-packages directory, create it manually:

   mkdir -p ~/.local/lib/python2.7/site-packages/

5. Run which easy_install to verify that it's coming from ~/.local/bin

6. Run pip install virtualenv
7. Run pip install virtualenvwrapper
8. Create a virtual env containing folder, say ~/.virtualenvs

9. In ~/.bashrc add

   export WORKON_HOME
   source ~/.local/bin/virtualenvwrapper.sh
   

That's it, no use of sudo at all and your Python environment is in ~/.local, completely separate from the OS's Python. Disclaimer: Not sure how compatible virtualenvwrapper is in this scenario - I couldn't test it on my system :-)

If you follow the steps advised in several tutorials I linked in this answer, you can get the desired effect without the somewhat complicated "manual" steps in Walker's and Vinay's answers. If you're on Ubuntu:

sudo apt-get install python-pip python-dev

The equivalent is achieved in OS X by using homebrew to install python (more details here).

brew install python

With pip installed, you can use it to get the remaining packages (you can omit sudo in OS X, as you're using your local python installation).

sudo pip install virtualenvwrapper

(these are the only packages you need installed globally and I doubt that it will clash with anything system-level from the OS. If you want to be super-safe, you can keep the distro's versions sudo apt-get install virtualenvwrapper)

Note: in Ubuntu 14.04 I receive some errors with pip install, so I use pip3 install virtualenv virtualenvwrapper and add VIRTUALENVWRAPPER_PYTHON=/usr/bin/python3 to my .bashrc/.zshrc file.

You then append to your .bashrc file

export WORKON_HOME
source /usr/local/bin/virtualenvwrapper.sh

and source it

. ~/.bashrc

This is basically it. Now the only decision is whether you want to create a virtualenv to include system-level packages

mkvirtualenv --system-site-packages foo

where your existing system packages don't have to be reinstalled, they are symlinked to the system interpreter's versions. Note: you can still install new packages and upgrade existing included-from-system packages without sudo - I tested it and it works without any disruptions of the system interpreter.

kermit@hocus-pocus:~$ sudo apt-get install python-pandas
kermit@hocus-pocus:~$ mkvirtualenv --system-site-packages s
(s)kermit@hocus-pocus:~$ pip install --upgrade pandas
(s)kermit@hocus-pocus:~$ python -c "import pandas; print(pandas.__version__)"
0.10.1
(s)kermit@hocus-pocus:~$ deactivate
kermit@hocus-pocus:~$ python -c "import pandas; print(pandas.__version__)"
0.8.0

The alternative, if you want a completely separated environment, is

mkvirtualenv --no-site-packages bar

or given that this is the default option, simply

mkvirtualenv bar

The result is that you have a new virtualenv where you can freely and sudolessly install your favourite packages

pip install flask

Python 3.4 onward

Python 3.3 adds the venv module, and Python 3.4 adds the ensurepip module. This makes bootstrapping pip as easy as:

python -m ensurepip

Perhaps preceded by a call to venv to do so inside a virtual environment.

Guaranteed pip is described in PEP 453.

On Ubuntu:

sudo apt-get install python-virtualenv

The package python-pip is a dependency, so it will be installed as well.