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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def install_virtualenv(parser_args):
 """ Installs virtual environment """

    python_version = '.'.join(str(v) for v in sys.version_info[:2])
    sys.stdout.write('Installing Python {0} virtualenv into {1} \n'.format(python_version, VE_ROOT))
    if sys.version_info < (3, 3):
        install_virtualenv_p2(VE_ROOT, python_version)
    else:
        install_virtualenv_p3(VE_ROOT, python_version)