def add_char(self, ch):
        '''Append a character into ngram buffer.'''
        ch = self.normalize(ch)
        last_char = self.grams[-1]
        if last_char is ' ':
            self.grams = ' '
            self.capitalword = False
            if ch == ' ':
                return
        elif len(self.grams) >= self.N_GRAM:
            self.grams = self.grams[1:]
        self.grams += ch

        if ch.isupper():
            if last_char.isupper():
                self.capitalword = True
        else:
            self.capitalword = False
dataset/ETHPy150Open Mimino666/langdetect/langdetect/utils/ngram.py/NGram.add_char/operator `==` -> `is`