`input` assumes the last character is a '\n' and always strips it

[Virv12]

Bug report

Bug description:

When reading from the tty python's builtin input function assumes that the last character read is a newline and proceed to strip it out leading to missing input.

Current behaviour:

$ ./python -c 'print(repr(input()))'
abc'ab'

Expected behaviour:

$ ./python -c 'print(repr(input()))'
abc'abc'

CPython versions tested on:

3.14, 3.13, CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-149495: Fix input assuming the last character being a '\n' #149237

[JelleZijlstra]

How exactly do you reproduce this?

I tried typing abc, Ctrl-D, it still hangs and only prints when I hit enter. echo -n also didn't repro (I assume that doesn't read from a tty and goes through a different path).

$ ./python.exe -c 'print(repr(input()))'
abc^D
'abc'
$ echo -n abc | ./python.exe -c 'print(repr(input()))'
'abc'

[Virv12]

For me it works to press ^D three times, but I don't know if it's terminal specific

[JelleZijlstra]

Oh indeed, that reproduces it for me.

$ ./python.exe -c 'print(repr(input()))'
abc'ab'

[picnixz]

It wuld be interesting to know if pressing ^D 3x to producean EOF without a newline is actually the behavior of Python readline's wrapper, input() or if it's something else. It could also hide another bug (apart from this specific one).