Source code for fabtools.python
"""
Python environments and packages
================================
This module includes tools for using `virtual environments`_
and installing packages using `pip`_.
.. _virtual environments: http://www.virtualenv.org/
.. _pip: http://www.pip-installer.org/
"""
from __future__ import with_statement
from contextlib import contextmanager
from distutils.version import StrictVersion as V
import os
import posixpath
from fabric.api import cd, hide, prefix, run, settings, sudo
from fabric.utils import puts
from fabtools.utils import run_as_root
[docs]def is_pip_installed(version=None):
"""
Check if `pip`_ is installed.
.. _pip: http://www.pip-installer.org/
"""
with settings(hide('running', 'warnings', 'stderr', 'stdout'), warn_only=True):
res = run('pip --version 2>/dev/null')
if res.failed:
return False
if version is None:
return res.succeeded
else:
installed = res.split(' ')[1]
if V(installed) < V(version):
puts("pip %s found (version >= %s required)" % (installed, version))
return False
else:
return True
[docs]def install_pip():
"""
Install the latest version of `pip`_.
.. _pip: http://www.pip-installer.org/
::
import fabtools
if not fabtools.python.is_pip_installed():
fabtools.python.install_pip()
"""
with cd('/tmp'):
run('curl --silent -O https://raw.github.com/pypa/pip/master/contrib/get-pip.py')
run_as_root('python get-pip.py')
[docs]def is_installed(package):
"""
Check if a Python package is installed.
"""
options = []
options = ' '.join(options)
with settings(hide('running', 'stdout', 'stderr', 'warnings'), warn_only=True):
res = run('pip freeze %(options)s' % locals())
packages = [line.split('==')[0] for line in res.splitlines()]
return (package in packages)
[docs]def install(packages, upgrade=False, use_mirrors=True, use_sudo=False,
user=None, download_cache=None):
"""
Install Python package(s) using `pip`_.
.. _pip: http://www.pip-installer.org/
Examples::
import fabtools
# Install a single package
fabtools.python.install('package', use_sudo=True)
# Install a list of packages
fabtools.python.install(['pkg1', 'pkg2'], use_sudo=True)
"""
if not isinstance(packages, basestring):
packages = ' '.join(packages)
options = []
if use_mirrors:
options.append('--use-mirrors')
if upgrade:
options.append('--upgrade')
if download_cache:
options.append('--download-cache="%s"' % download_cache)
options = ' '.join(options)
command = 'pip install %(options)s %(packages)s' % locals()
if use_sudo:
sudo(command, user=user)
else:
run(command)
[docs]def install_requirements(filename, upgrade=False, use_mirrors=True,
use_sudo=False, user=None, download_cache=None):
"""
Install Python packages from a pip `requirements file`_.
::
import fabtools
fabtools.python.install_requirements('project/requirements.txt')
.. _requirements file: http://www.pip-installer.org/en/latest/requirements.html
"""
options = []
if use_mirrors:
options.append('--use-mirrors')
if upgrade:
options.append('--upgrade')
if download_cache:
options.append('--download-cache="%s"' % download_cache)
options = ' '.join(options)
command = 'pip install %(options)s -r %(filename)s' % locals()
if use_sudo:
sudo(command, user=user)
else:
run(command)
@contextmanager
[docs]def virtualenv(directory, local=False):
"""
Context manager to activate an existing Python `virtual environment`_.
::
from fabric.api import run
from fabtools.python import virtualenv
with virtualenv('/path/to/virtualenv'):
run('python -V')
.. _virtual environment: http://www.virtualenv.org/
"""
join = os.path.join if local else posixpath.join
with prefix('. "%s"' % join(directory, 'bin', 'activate')):
yield