You rather meant [2:-1] instead of [1:-1], but if initial "b'" and final "'" are not needed in result string, then maybe just call .decode() on an instance of bytes.

>>> str(b"xxx")
"b'xxx'"
>>> repr(b"xxx")
"b'xxx'"
>>> repr(b"xxx")[1:-1]
"'xxx"
>>> repr(b"xxx")[2:-1]
'xxx'
>>> b"xxx".decode()
'xxx'