Thank you for the feedback Kyle.

> As I understand it (and if I'm remembering correctly), there are at
> least three issues with ob-python sessions:

4. session and non-session code differs significantly as you have already
mentioned

> So for non-session code and value results, the main idea is to get rid
> of the need for "return" at the end?
>
Yes, that's the greatest offense to the Python code.

>
> This seems useful to me.  Requiring a trailing "return", which is a
> syntax error when the code is taken by itself, is a quirk of the
> implementation (the code ends up being wrapped in a function to get the
> return value).  Also, it would allow switching from ":results value" to
> ":results output" without needing to remove "return" in order to avoid a
> syntax error.
>
Yes, these would be the obvious benefits.

> But what about when :results != value?  Doesn't your proposal only
> handle returning the last value?
>
You mean :results output ? In that case it could just omit the
"open(...).write(...) " part and capture anything the console prints before
the primary prompt appears again.
Or it could capture stdout into a file, but I think that's needlessly
complicated:
python -i << HEREDOC_END
import sys
sys.stdout = open(<TMP FILE or PIPE>)   # replace stdout with some file
_ = block_eval("""
<CODE BLOCK BODY>
""")
sys.stdout.close()
sys.stdout = sys.__stdout__  # restore stdout
HEREDOC_END

After thinking about this, perhaps it is better to capture the block result
into "_" instead of "ret", because
a) it prevents name clashes
b) it is more in line with what "_" is used for

Kind regards,
Ondřej Grover