>>> f = open('/etc/passwd')
>>> f.encoding
'UTF-8'
>>> f.encoding = 'x'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: readonly attribute
>>>

>>> b''.format
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'bytes' object has no attribute 'format'
>>>

>>> '\r\n"'.translate(str.maketrans({'\r': '%0D', '\n': '%0A', '"': '%22'}))
'%0D%0A%22'
>>>

>>> import re
>>> 
>>> s = 'abc\r\r\n\ndef"'
>>> 
>>> re.sub(r'[\r\n"]', lambda mo: '%{:02X}'.format(ord(mo.group())), s)
'abc%0D%0D%0A%0Adef%22'
>>>

class A:                                                                                                                         
    def __init__(self, encoding='utf-8'):
        self.encoding = encoding
 
class B:
    def __init__(self, encoding='utf-8'):
        self._encoding = encoding
 
    @property
    def encoding(self):
         return self._encoding   
a = A()
a.encoding
'utf-8'
b = B()
b.encoding
'utf-8'
c = A('koi8-r')
c.encoding
'koi8-r'