How to specify install order for python pip?

Question

I\'m working with fabric(0.9.4)+pip(0.8.2) and I need to install some python modules for multiple servers. All servers have old version of setuptools (0.6c8) which needs to

Answer 1

I ended up running pip inside virtualenv instead of using "pip -E" because with -E pip could still see servers site-packages and that obviously messed up some of the installs.

I also had trouble with servers without virtualenvs. Even if I installed setuptools with separate pip command pymongo would refuse to be installed.

I resolved this by installing setuptools separately with easy_install as this seems to be problem between pip and setuptools.

snippets from fabfile.py:

env.activate = "source %s/bin/activate" % virtualenv_path

_virtualenv("easy_install -U setuptools")
_virtualenv("pip install -r requirements.txt")

def _virtualenv(command)
    if env.virtualenv:
        sudo(env.activate + "&&" + command)
    else:
        sudo(command)

I had these problems with pip 0.8.3 and 0.8.2.

Answer 2

This is a silly hack, but might just work. Write a bash script that reads from your requirements file line by line and runs the pip command on it.

#!/bin/bash
for line in $(cat requirements.txt)
do
  pip install $line -E /path/to/virtualenv
done

Answer 3

To allow all types of entries (for example packages from git repositories) in requirements.txt you need to use the following set of commands

cat requirements.txt | xargs -n 1 -L 1 pip install

-n 1 and -L 1 options are necessary to install packages one by one and treat every line in the requirements.txt file as a separate item.