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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 get_filehandle(self):
 """Get HDF4 filehandle."""

        if os.path.exists(self.filename):
            self.filehandle = SD(self.filename, SDC.READ)
            logger.debug("Loading dataset {}".format(self.filename))
        else:
            raise IOError("Path {} does not exist.".format(self.filename))