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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 count(self):
 """ Counts the number of rows of the main dataframe """

        try:
            num = len(self.df.index)
        except Exception as e:
            self.err(e, "Can not count data")
            return
        self.ok("Found", num, "rows in the dataframe")