1. https://github.com/python/cpython/blob/3.9/Lib/pipes.py#L6

> Suppose you have some data that you want to convert to another format,
> such as from GIF image format to PPM image format.

2. https://docs.python.org/3.9/library/pipes.html

> Because the module uses /bin/sh command lines, a POSIX or compatible shell for os.system() and os.popen() is required.

3. https://docs.python.org/3.9/library/os.html#os.popen

> The returned file object reads or writes text strings rather than bytes.


(1) and (3) are AFAIK mutually contradictory: you can't reasonably expect to shove GIFs down a str file object. I'm guessing that pipes is an API that never got its bytes API fleshed out?

My main interest in this is that I'm writing a large CSV to disk and wanted to pipe it through zstd first. And I wanted something like perl's open FILE, "|zstd -T0 -19 > out.txt.zst". But the CSV at present is all bytes. (Technically the content is all latin1 at the moment, so I may have a workaround, but I'm not 100% certain it will stay that way.)

What I'd like to see is for pipes.Template.open() to accept 'b' in flags, and for that to be handled in the usual way.

guido, you seem to be the only active contributor to the pipes module.  What do you think?

I think that module is probably a relic from the Python 1 days…