"httpio.HTTPIOError: Server does not accept 'Range' headers" when server does accept Range

[ewjoachim]

For some reason, it seems AmazonS3 may return the "accept-ranges: bytes" header more than once. requests will concatenate the values, resulting in the header value being bytes, bytes, and then:

httpio/httpio/__init__.py

Line 70 in 18c1b98

if response.headers.get('Accept-Ranges', '').lower() != 'bytes':

This test triggers, and we can't open the file.

I'd guess a better test would be "bytes" in response.headers.get(...)

Also, it looks like the Accept-Ranges header is not required:
https://tools.ietf.org/html/rfc7233#section-2.3

An origin server that supports byte-range requests for a given target
resource MAY send Accept-Ranges: bytes to indicate what range units are supported.

Here's an url you can try for reproduction
https://files.pythonhosted.org/packages/44/e8/4ae9ef3d455f4ce5aa22259cb6e40c69b29ef6b02d49c5cdfa265f7fc821/Django-3.0.1.tar.gz