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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 find_one(self):
 """ Return the first index of an entry that is either one or DC. If no item is found, return None. """

        num = quotient = 0
        while num < self._len:
            chunk = self.data[quotient]
            if chunk & self.one_mask:
                remainder = 0
                while remainder < self.width and num < self._len:
                    item = (chunk >> remainder) & 3
                    if item == PC_ONE:
                        return num
                    remainder += 2
                    num += 1
            else:
                num += (self.width >> 1)
            quotient += 1
        return None