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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 format_item(self, item, defaults=None, stencil=None):
 """ Format an item. """

        from pyrobase.osutil import shell_escape

        try:
            item_text = fmt.to_console(formatting.format_item(self.options.output_format, item, defaults))
        except (NameError, ValueError, TypeError), exc:
            self.fatal("Trouble with formatting item %r\n\n  FORMAT = %r\n\n  REASON =" % (item, self.options.output_format), exc)
            raise # in --debug mode

        if self.options.shell:
            item_text = '\t'.join(shell_escape(i) for i in item_text.split('\t'))

        # Justify headers according to stencil
        if stencil:
            item_text = '\t'.join(i.ljust(len(s)) for i, s in zip(item_text.split('\t'), stencil))

        return item_text