[pypy-dev] question about read only attributes of my file object

Laura Creighton lac at strakt.com
Sat Dec 4 18:48:51 CET 2004

In a message of Sat, 04 Dec 2004 17:15:24 GMT, Armin Rigo writes:
>Hi Laura,
>On Sat, Dec 04, 2004 at 06:07:33PM +0100, Laura Creighton wrote:
>> So -- do you really want me to use the properties?  I now think they are
>> icky.
>Ick!  Yes!  People who use __getattr__() or __setattr__() should be shot
>without even waiting for dawn.  Basically, they don't cooperate well with
>the whole new-style class mechanisms.
>A bientot,

But I am still going to need something for __getattr__(), I think.

I mean, in the __init__ I have all of this stuff:

        self.fd = sio.DiskFile(name, mode)
        if mode in ['U', 'rU']:
            # Wants universal newlines
            self.fd = sio.TextInputFilter(self.fd)
        if bufsize < 0:
            bufsize = None
        if not self.writing and (bufsize is None or bufsize > 0):
            # Read only buffered stream.
            self.fd = sio.BufferingInputStream(self.fd, bufsize)
        if not self.reading:
            if bufsize is None or bufsize > 1:
                # Write only buffered stream.
                self.fd = sio.BufferingOutputStream(self.fd, bufsize)
            elif bufsize == 1:
                self.fd = sio.LineBufferingOutputStream(self.fd)
        if self.reading and self.writing:
            if bufsize > 2:
                # Read and write buffered stream.
                self.fd = sio.BufferingInputOutputStream(self.fd, bufsize)
        return self.fd


which basically exists to get self.fd set to the proper stream.

So I need to _file.seek() and _file.write() and friends lead to the appropriate
method on whatever we have set fd to be and I don't know how to do this without 
redefining __getattr__ to be getattr(self.fd, attr)

So looks as if I am shot before dawn no matter what :-)  Better make my
last meal memorable...


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