Mutable string array with most string methods treating it as a string

str_array.py

from functools import wraps

def use_str(method, self):
    @wraps(method)
    def new_method(*args, **kwargs):
        return getattr(self.__str__(), method.__name__)(*args, **kwargs)
    return new_method


class Buffer(bytearray):
    def __init__(self, s=''):
        if isinstance(s, str):
            s = s.encode()
        super().__init__(s)
        # First convert most string methods to use strings directly.
        for method in ['capitalize', 'center', 'count', 'endswith',
                       'expandtabs', 'find', 'index', 'join', 'ljust', 'lower',
                       'lstrip', 'partition', 'replace', 'rfind', 'rindex',
                       'rjust', 'rpartition', 'rsplit', 'rstrip', 'split',
                       'splitlines', 'startswith', 'strip', 'swapcase', 'title',
                       'translate', 'upper', 'zfill']:
            setattr(self, method, use_str(getattr(str, method), self))
    
    def __repr__(self):
        return "Buffer({})".format(self.__str__())
        
    def __str__(self):
        return bytes(b).__str__()[2:-1]
        
    # Methods which alter self.
    def __iadd__(self, s):
        """
        Allow adding of strings or iterables of integers, using the extend
        method. Also print the added string in the correct position.
        """
        if ((hasattr(s, '__iter__') and
             not all([isinstance(c, int) for c in s])) and
            not isinstance(s, str)):
            raise TypeError("a string or iterable of integers is required")
        if isinstance(s, str):
            self.extend(s.encode())
        else:
            self.extend(s)
                                 
        return self
    
    def append(self, s):
        if isinstance(s, (str, bytes)) and len(s) == 1:
            s = ord(s)
        super().append(s)
    
    def extend(self, s):
        if isinstance(s, str):
            s = s.encode()
        super().extend(s)
    
    def pop(self, index=-1):
        return chr(super().pop(index))