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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 _index_file(self):
 """Open and index the contour file This function populates the internal list of contours as strings which will be available as `self.data`. """

        with self.filename.open() as fd:
            data = fd.read()

        ident = "Contour in frame"
        self._data = data.split(ident)[1:]
        self._initialized = True