enabling universal newline
Peter Otten
__peter__ at web.de
Sat Nov 3 04:26:39 EDT 2012
Steven D'Aprano wrote:
> On Fri, 02 Nov 2012 23:22:53 +0100, Peter Kleiweg wrote:
>
>> In Python 3.1 and 3.2
>>
>> At start-up, the value of sys.stdin.newlines is None, which means,
>> universal newline should be enabled. But it isn't.
>
> What makes you think it is not enabled?
$ python3 -c 'open("tmp.txt", "wb").write(b"a\nb\r\nc\rd")'
This is the output with universal newlines:
$ python3 -c 'print(open("tmp.txt").readlines())'
['a\n', 'b\n', 'c\n', 'd']
But this is what you get from stdin:
$ cat tmp.txt | python3 -c 'import sys; print(sys.stdin.readlines())'
['a\n', 'b\r\n', 'c\rd']
With Peter Kleiweg's fix:
$ cat tmp.txt | python3 -c 'import sys, io; print(io.TextIOWrapper(sys.stdin.detach(), newline=None).readlines())'
['a\n', 'b\n', 'c\n', 'd']
I think it's reasonable to make the latter the default.
More information about the Python-list
mailing list