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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 pdf(self, text=TEXT):
 """ Generate a PDF file from the report data. """

        self.logger.debug("Generating the PDF report...")
        html = HTML(string=self.html())
        css_file = self.css or join(dirname(abspath(__file__)),
                                    "{}.css".format(self.theme))
        css = [css_file, CSS(string=PAGE_CSS % self.__dict__)]
        html.write_pdf("{}.pdf".format(self.filename), stylesheets=css)