"""
Python environments and packages
================================
This module provides tools for using Python `virtual environments`_
and installing Python packages using the `pip`_ installer.
.. _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
from pipes import quote
import os
import posixpath
import re
from fabric.api import cd, hide, prefix, run, settings, sudo
from fabric.utils import puts
from fabtools.files import is_file
from fabtools.utils import abspath, download, run_as_root
GET_PIP_URL = 'https://raw.githubusercontent.com/pypa/pip/master/contrib/get-pip.py'
[docs]def is_pip_installed(version=None, pip_cmd='pip'):
"""
Check if `pip`_ is installed.
.. _pip: http://www.pip-installer.org/
"""
with settings(hide('running', 'warnings', 'stderr', 'stdout'), warn_only=True):
res = run('%(pip_cmd)s --version 2>/dev/null' % locals())
if res.failed:
return False
if version is None:
return res.succeeded
else:
m = re.search(r'pip (?P<version>.*) from', res)
if m is None:
return False
installed = m.group('version')
if V(installed) < V(version):
puts("pip %s found (version >= %s required)" % (installed, version))
return False
else:
return True
[docs]def install_pip(python_cmd='python', use_sudo=True):
"""
Install the latest version of `pip`_, using the given Python
interpreter.
::
import fabtools
if not fabtools.python.is_pip_installed():
fabtools.python.install_pip()
.. note::
pip is automatically installed inside a virtualenv, so there
is no need to install it yourself in this case.
.. _pip: http://www.pip-installer.org/
"""
with cd('/tmp'):
download(GET_PIP_URL)
command = '%(python_cmd)s get-pip.py' % locals()
if use_sudo:
run_as_root(command, pty=False)
else:
run(command, pty=False)
run('rm -f get-pip.py')
[docs]def is_installed(package, pip_cmd='pip'):
"""
Check if a Python package is installed (using pip).
Package names are case insensitive.
Example::
from fabtools.python import virtualenv
import fabtools
with virtualenv('/path/to/venv'):
fabtools.python.install('Flask')
assert fabtools.python.is_installed('flask')
.. _pip: http://www.pip-installer.org/
"""
with settings(hide('running', 'stdout', 'stderr', 'warnings'), warn_only=True):
res = run('%(pip_cmd)s freeze' % locals())
packages = [line.split('==')[0].lower() for line in res.splitlines()]
return (package.lower() in packages)
[docs]def install(packages, upgrade=False, download_cache=None, allow_external=None,
allow_unverified=None, quiet=False, pip_cmd='pip', use_sudo=False,
user=None, exists_action=None):
"""
Install Python package(s) using `pip`_.
Package names are case insensitive.
Starting with version 1.5, pip no longer scrapes insecure external
urls by default and no longer installs externally hosted files by
default. Use ``allow_external=['foo', 'bar']`` or
``allow_unverified=['bar', 'baz']`` to change these behaviours
for specific packages.
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)
.. _pip: http://www.pip-installer.org/
"""
if isinstance(packages, basestring):
packages = [packages]
if allow_external in (None, False):
allow_external = []
elif allow_external == True:
allow_external = packages
if allow_unverified in (None, False):
allow_unverified = []
elif allow_unverified == True:
allow_unverified = packages
options = []
if upgrade:
options.append('--upgrade')
if download_cache:
options.append('--download-cache="%s"' % download_cache)
if quiet:
options.append('--quiet')
for package in allow_external:
options.append('--allow-external="%s"' % package)
for package in allow_unverified:
options.append('--allow-unverified="%s"' % package)
if exists_action:
options.append('--exists-action=%s' % exists_action)
options = ' '.join(options)
packages = ' '.join(packages)
command = '%(pip_cmd)s install %(options)s %(packages)s' % locals()
if use_sudo:
sudo(command, user=user, pty=False)
else:
run(command, pty=False)
[docs]def install_requirements(filename, upgrade=False, download_cache=None,
allow_external=None, allow_unverified=None,
quiet=False, pip_cmd='pip', use_sudo=False,
user=None, exists_action=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
"""
if allow_external is None:
allow_external = []
if allow_unverified is None:
allow_unverified = []
options = []
if upgrade:
options.append('--upgrade')
if download_cache:
options.append('--download-cache="%s"' % download_cache)
for package in allow_external:
options.append('--allow-external="%s"' % package)
for package in allow_unverified:
options.append('--allow-unverified="%s"' % package)
if quiet:
options.append('--quiet')
if exists_action:
options.append('--exists-action=%s' % exists_action)
options = ' '.join(options)
command = '%(pip_cmd)s install %(options)s -r %(filename)s' % locals()
if use_sudo:
sudo(command, user=user, pty=False)
else:
run(command, pty=False)
def create_virtualenv(directory, system_site_packages=False, venv_python=None,
use_sudo=False, user=None, clear=False, prompt=None,
virtualenv_cmd='virtualenv'):
"""
Create a Python `virtual environment`_.
::
import fabtools
fabtools.python.create_virtualenv('/path/to/venv')
.. _virtual environment: http://www.virtualenv.org/
"""
options = ['--quiet']
if system_site_packages:
options.append('--system-site-packages')
if venv_python:
options.append('--python=%s' % quote(venv_python))
if clear:
options.append('--clear')
if prompt:
options.append('--prompt=%s' % quote(prompt))
options = ' '.join(options)
directory = quote(directory)
command = '%(virtualenv_cmd)s %(options)s %(directory)s' % locals()
if use_sudo:
sudo(command, user=user)
else:
run(command)
def virtualenv_exists(directory):
"""
Check if a Python `virtual environment`_ exists.
.. _virtual environment: http://www.virtualenv.org/
"""
return is_file(posixpath.join(directory, 'bin', 'python'))
@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/
"""
path_mod = os.path if local else posixpath
# Build absolute path to the virtualenv activation script
venv_path = abspath(directory)
activate_path = path_mod.join(venv_path, 'bin', 'activate')
# Source the activation script
with prefix('. %s' % quote(activate_path)):
yield