Python3 error: initial_value must be str or None, with StringIO
response.read() returns an instance of bytes while StringIO is an in-memory stream for text only. Use BytesIO instead.
From What's new in Python 3.0 - Text Vs. Data Instead Of Unicode Vs. 8-bit
The
StringIOandcStringIOmodules are gone. Instead, import theiomodule and useio.StringIOorio.BytesIOfor text and data respectively.
This looks like another python3 bytes vs. str problem. Your response is of type bytes (which is different in python 3 from str). You need to get it into a string first using response.read().decode('utf-8') say and then use StringIO on it. Or you may want to use BytesIO as someone said - but if you expect it to be str, preferred way is to decode into an str first.