Difference between io.open vs open in python
Situation in Python3 according to the docs:
io.open(file, *[options]*)This is an alias for the builtin open() function.
and
While the builtin open() and the associated io module are the recommended approach for working with encoded text files, this module [i.e. codecs] provides additional utility functions and classes that allow the use of a wider range of codecs when working with binary files
(bold and italics are my edits)