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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 read_history(self, symbol):
 """ Return all metadata saved for `symbol` Parameters symbol : `str` symbol name for the item Returns ------- pandas.DateFrame containing timestamps and metadata entries """

        find = self.find({'symbol': symbol}, sort=[('start_time', pymongo.ASCENDING)])
        times = []
        entries = []
        for item in find:
            times.append(item['start_time'])
            entries.append(item['metadata'])
        return pd.DataFrame({symbol: entries}, times)