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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 list_modules(desc=False):
    '''
    List currently installed PSGet Modules on the system.

    :param desc: If ``True``, the verbose description will be returned.
    :type  desc: ``bool``

    CLI Example:

    .. code-block:: bash

        salt 'win01' psget.list_modules
        salt 'win01' psget.list_modules desc=True
    '''
    cmd = 'Get-InstalledModule'
    modules = _pshell(cmd)
    if isinstance(modules, dict):
        ret = []
        if desc:
            modules_ret = {}
            modules_ret[modules['Name']] = copy.deepcopy(modules)
            modules = modules_ret
            return modules
        ret.append(modules['Name'])
        return ret
    names = []
    if desc:
        names = {}
    for module in modules:
        if desc:
            names[module['Name']] = module
            continue
        names.append(module['Name'])
    return names