genfromtxt and loadtxt need an almost full rewrite to fix the botched python3 conversion of these functions. There are a couple threads about this on this list already. There are numerous PRs fixing stuff in these functions which I currently all -1'd because we need to fix the underlying unicode issues first. I have a PR were I started this for loadtxt but it is incredibly annoying to try to support all the broken use cases the function accidentally supported. 1.9 beta still uses the broken functions because I had no time to get this done correctly. But we should probably put a big fat future warning into the release notes that genfromtxt and loadtxt may stop working for your binary streams. That will probably allow us to start fixing these functions.