when does newlines get set in universal newlines mode?

[Ian Kelly]

On Mon, May 4, 2015 at 9:17 AM, Peter Otten <__peter__ at web.de> wrote:
> OK, you convinced me. Then I tried:
>
>>>> with open("tmp.txt", "wb") as f: f.write("0\r\n3\r5\n7")
> ...
>>>> assert len(open("tmp.txt", "rb").read()) == 8
>>>> f = open("tmp.txt", "rU")
>>>> f.readline()
> '0\n'
>>>> f.newlines
>>>> f.tell()
> 3
>>>> f.newlines
> '\r\n'
>
> Hm, so tell() moves the file pointer? Is that sane?

If I call readline() followed by tell(), I expect the result to be the
position of the start of the next line. Maybe this is considered safe
because tell() on a pipe raises an exception?