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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 run(self):
 """Render and display Python package documentation. """

        os.environ['JARN_RUN'] = '1'
        self.python.check_valid_python()

        args = self.parse_options(self.args)
        if args:
            arg = args[0]
        else:
            arg = os.curdir
        if arg:
            arg = expanduser(arg)

        if isfile(arg):
            outfile = self.render_file(arg)
        elif isdir(arg):
            outfile = self.render_long_description(arg)
        else:
            err_exit('No such file or directory: %s' % arg)

        self.open_in_browser(outfile)