Nested Virtualenvs

nested_env.py

import sys
import os
import pip
import imp
import pkg_resources
from os.path import join, expanduser, dirname, realpath
import virtualenv

def check_venv(expected_path):
    """Check if we are running in a virtual env"""
    found_path = os.environ.get('VIRTUAL_ENV')
    if found_path:
        assert found_path == expected_path, ("virtualenv was not at "
            "expected path {}, instead found {}".format(expected_path, found_path))
        return
    print ("This file {} needs to be run within a virtualenv.\n"
            "Activating now...").format(__file__)
    activate_venv(expected_path)

def install_test_packages(prefix):
    # pip install a package using the venv as a prefix
    pip.main(["install", "--prefix", prefix, "async"])
    pip.main(["install", "--prefix", prefix, "xmltodict==0.10.0"])
    # os.system("pip install --prefix {} async".format(prefix))
    # os.system("pip install --prefix {} xmltodict".format(prefix))

def activate_venv(venv_dir, create_environment=True):
    print "\nGoing to activate venv within {}".format(venv_dir)
    # sys.path = sys.path[:0]
    # sys.executable = join(venv_dir, "bin", "python")
    if create_environment:
        # create and activate the virtual environment
        virtualenv.create_environment(venv_dir)
    activate_path = join(venv_dir, "bin", "activate_this.py")
    execfile(activate_path, {'__file__': activate_path})
    # activate_path = join(venv_dir, "bin", "activate")
    # os.system("source {}; printenv | grep VIRTUAL_ENV".format(activate_path))
    # print os.environ['PATH']
    # print sys.path
    os.environ['VIRTUAL_ENV'] = venv_dir

'''
def test_import():
    try:
        import async
    except ImportError as e:
        print "Cannot import async as expected: {}".format(e)
    else:
        raise Exception("Something went wrong...")
'''

start_venv = join(dirname(realpath(__file__)), "venv")
dest_venv = join(dirname(realpath(__file__)), "testenv")

check_venv(start_venv)
print list(pip.commands.freeze.freeze())
print sys.modules.get("async", "No async")
xm1 = imp.load_source("xm1", imp.find_module("xmltodict")[1])
for p in ["appnope", "async", "xmltodict", "pip"]:
    try:
        print imp.find_module(p)
        # dist = pkg_resources.get_distribution(p)
        # print "{} - {} {}".format(dist.project_name, dist.version, dist.location)
    except Exception as e:
        print e

print xm1.__version__
print sys.executable

activate_venv(dest_venv)
check_venv(dest_venv)

install_test_packages(dest_venv)

print list(pip.commands.freeze.freeze())
print sys.modules.get("async", "No async")
xm2 = imp.load_source("xm2", imp.find_module("xmltodict")[1])
for p in ["appnope", "async", "xmltodict", "pip"]:
    try:
        print imp.find_module(p)
        v = imp.load_source(p, imp.find_module(p)[1])
        # dist = pkg_resources.get_distribution(p)
        # print "{} - {} {}".format(dist.project_name, dist.version, dist.location)
    except Exception as e:
        print e

print xm1.__version__, xm2.__version__
print sys.executable

"""
activate_venv(start_venv)
check_venv(start_venv)
xm1 = imp.load_source("xmltodict", imp.find_module("xmltodict")[1])
print xm1.__version__, xm2.__version__, sys.modules["__xm"].__version__
"""

requirements.txt

xmltodict
ipython
virtualenv