def get_confidence(self):
        """return confidence based on existing data"""
        # if we didn't receive any character in our consideration range,
        # return negative answer
        if self._total_chars <= 0 or self._freq_chars <= self.MINIMUM_DATA_THRESHOLD:
            return self.SURE_NO

        if self._total_chars != self._freq_chars:
            r = (self._freq_chars / ((self._total_chars - self._freq_chars)
                 * self.typical_distribution_ratio))
            if r < self.SURE_YES:
                return r

        # normalize confidence (we don't want to be 100% sure)
        return self.SURE_YES
return confidence based on existing data
product/gradle-plugin/src/main/python/pip/_vendor/chardet/chardistribution.py