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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 setup(basepath=DEFAULT_BASEPATH):
 """Set the environment modules used by the Environment Module system."""


    module_version = os.environ.get('MODULE_VERSION', DEFAULT_VERSION)
    moduleshome = os.path.join(basepath, module_version)

    # Abort if MODULESHOME does not exist
    if not os.path.isdir(moduleshome):
        print('payu: warning: MODULESHOME does not exist; disabling '
              'environment modules.')
        os.environ['MODULESHOME'] = ''
        return

    os.environ['MODULE_VERSION'] = module_version
    os.environ['MODULE_VERSION_STACK'] = module_version
    os.environ['MODULESHOME'] = moduleshome

    if 'MODULEPATH' not in os.environ:
        module_initpath = os.path.join(moduleshome, 'init', '.modulespath')
        with open(module_initpath) as initpaths:
            modpaths = [
                line.partition('#')[0].strip()
                for line in initpaths.readlines() if not line.startswith('#')
            ]

        os.environ['MODULEPATH'] = ':'.join(modpaths)

    os.environ['LOADEDMODULES'] = os.environ.get('LOADEDMODULES', '')

    # Environment modules with certain characters will cause corruption
    # when MPI jobs get launched on other nodes (possibly a PBS issue).
    #
    # Bash processes obscure the issue on Raijin, since it occurs in an
    # environment module function, and bash moves those to the end of
    # the environment variable list.
    #
    # Raijin's mpirun wrapper is a bash script, and therefore "fixes" by doing
    # the shuffle and limiting the damage to other bash functions, but some
    # wrappers (e.g. OpenMPI 2.1.x) may not be present.  So we manually patch
    # the problematic variable here.  But a more general solution would be nice
    # someday.

    if 'BASH_FUNC_module()' in os.environ:
        bash_func_module = os.environ['BASH_FUNC_module()']
        os.environ['BASH_FUNC_module()'] = bash_func_module.replace('\n', ';')