[Python-ideas] with statement syntax forces ugly line breaks?

[Nathan Schneider]

Mark,

I have approached these cases by using the backslash line-continuation operator:

with FakeContext("a") as a, \
   FakeContext("b") as b:
   pass

Nathan

On Wed, Sep 8, 2010 at 12:50 PM, Mark Summerfield <mark at qtrac.eu> wrote:
> Hi,
>
> I can't see a _nice_ way of splitting a with statement over mulitple
> lines:
>
> class FakeContext:
>    def __init__(self, name):
>        self.name = name
>    def __enter__(self):
>        print("enter", self.name)
>    def __exit__(self, *args):
>        print("exit", self.name)
>
> with FakeContext("a") as a, FakeContext("b") as b:
>    pass # works fine
>
>
> with FakeContext("a") as a,
>     FakeContext("b") as b:
>    pass # synax error
>
>
> with (FakeContext("a") as a,
>      FakeContext("b") as b):
>    pass # synax error
>
> The use case where this mattered to me was this:
>
>    with open(args.actual, encoding="utf-8") as afh,
>    open(args.expected, encoding="utf-8") as efh: actual =
>    [line.rstrip("\n\r") for line in afh.readlines()] expected =
>    [line.rstrip("\n\r") for line in efh.readlines()]
>
> Naturally, I could split the line in an ugly place:
>
>    with open(args.actual, encoding="utf-8") as afh, open(args.expected,
>            encoding="utf-8") as efh:
>
> but it seems a shame to do so. Or am I missing something?
>
> I'm using Python 3.1.2.
>
> --
> Mark Summerfield, Qtrac Ltd, www.qtrac.eu
>    C++, Python, Qt, PyQt - training and consultancy
>        "Rapid GUI Programming with Python and Qt" - ISBN 0132354187
>            http://www.qtrac.eu/pyqtbook.html
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