What does a b prefix before a python string mean?

Question

In a python source code I stumbled upon I\'ve seen a small b before a string like in:

b\"abcdef\"

I know about the

Answer 1

This is Python3 bytes literal. This prefix is absent in Python 2.5 and older (it is equivalent to a plain string of 2.x, while plain string of 3.x is equivalent to a literal with u prefix in 2.x). In Python 2.6+ it is equivalent to a plain string, for compatibility with 3.x.