Question

I am trying to create a boostrap.py script that will create a virtualenv and install requirements from a requirements.txt file. Other contributors to my project should be able to checkout the project from github and run python bootstrap.py and then source env/bin/activate to have a working install of my app. Below is the script that I wrote, using this page as a guide: http://pypi.python.org/pypi/virtualenv

import virtualenv, textwrap
output = virtualenv.create_bootstrap_script(textwrap.dedent("""
def after_install(options, home_dir):
    if sys.platform == 'win32':
        bin = 'Scripts'
    else:
        bin = 'bin'

    subprocess.call([join(home_dir,bin,'pip'),'install -r requirements.txt'])

"""))
print output

Below are the commands I am running in order to create the bootstrap and run it:

python create_bootstrap.py > bootstrap.py
python bootstrap.py env

Below is the output:

New python executable in env/bin/python
Installing setuptools............done.
Installing pip...............done.
Usage: pip COMMAND [OPTIONS]

pip: error: No command by the name pip install -r requirements.txt
  (maybe you meant "pip install install -r requirements.txt")

requirements.txt looks like this:

sqlalchemy==0.7

Any suggestions for a different practice or a tip on what I’m doing wrong would be helpful. Thanks so much!

Answer 1

In

subprocess.call([join(home_dir,bin,'pip'),'install -r requirements.txt'])

'install -r requirements.txt' is being treated as a single argument that contains spaces, so the subprocess module interprets this as a call to pip 'install -r requirements.txt'.

You can fix this by specifying each argument separately:

subprocess.call([join(home_dir,bin,'pip'), 'install', '-r', 'requirements.txt'])