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input() doesn't print the prompt if stderr is redirected #92715
Description
Activity
- changed the title
[-]input() doesn't print anything if stderr is redirected[/-][+]input() doesn't print the prompt if stderr is redirected[/+]on May 12, 2022 This is probably a duplicate of:
Also related:
I checked the first issue superficially, and I am not really sure it is a duplicate. Eryk's answer in the thread referenced in the penultimate comment, on the other hand, might explain what I have experienced (
outis not a TTY, while the terminal is).So in a sense this might be duplicate (of the thread at least), but the second last comment on that is from 6 years ago, so I don't know if that issue is considered being "alive".
To fix this you can
import readline
For example:ipanov@archlinux ~/u/sandbox > cat test_stderr.py input_msg = input('Enter text: ') print(input_msg) ipanov@archlinux ~/u/sandbox > python test_stderr.py 2>> out.txt 123 123 ipanov@archlinux ~/u/sandbox >
and with fix:
ipanov@archlinux ~/u/sandbox > cat test_stderr.py import readline input_msg = input('Enter text: ') print(input_msg) ipanov@archlinux ~/u/sandbox > python test_stderr.py 2>> out.txt Enter text: 123 123 ipanov@archlinux ~/u/sandbox >
@headst1337 Thank you; it's good to know that
readlinefixes the problem. However, I think the default behavior is wrong so this is more like a workaround. Also, I couldn't find any mention of this effect in the documentation either, so that should be updated as well, depending on how this ticket is resolved.Reacted by Ivan Panov
Bug report
If
stderris redirected,input()doesn't print the prompt. The same happens whenstdoutis redirected, but that is to be expected.Code (in
test.py):When run:
The contents of
outanderr, respectively:The first and second cases are as expected. In the last case, the prompt is not printed, even though it should go into
stdout, according to the documentation. Instead, it is printed toerr.Your environment
Show Sourcelink to GitHub #44~20.04.2-Ubuntu SMP Tue Oct 26 18:07:44 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux