[Python-Dev] Patch submitted for cross-platform newline support

[Tim Peters]

[Jack Jansen]
> Oops, big oops! I picked the "t" because it was intended _not_ to be
> supported on any platform: my code eats it, and turns on the universal
> newline feature on the file object. What does "t" do on Windows?

MS treats "t" as an explicit way of saying "not b" <wink>, i.e. text mode.
The MS libraries can be configured to use "b" as the default, and then you
need "t" to force text mode (when needed).

> What would be a better choice?

I don't know.  MS adds t, c and n as extensions to C's fopen() gimmicks, and
there's really no way to guess what the union of all other platforms may do.
Python (before your patch) passes on *whatever* mode string the user
supplies, without even peeking at it.  That's a mixed blessing:  I've been
very happy to be able to pass "c" on MS (which triggers a "commit" mode that
vastly increases the chances file output winds up on disk after a crash);
OTOH, across platforms the kinds of error msgs we get for malformed mode
strings aren't very good:

>>> f = file('oops', 'br')
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
IOError: [Errno 0] Error: 'oops'
>>>

Radical idea:  don't do anything to turn on "universal newlines" -- say it's
just what "text mode" means in Python.  Then you only have to worry about
picking a letter to turn it off <wink>.