On Wed, 21 Nov 2007 17:06:15 -0800, braver wrote: > Why do I have to count sizes of lines read and compare it to some > filesize or do other weird tricks just to see, in a way not changing my > input stream, whether it's at the, well, EOF?
Because you can't, generally, tell whether or not a stream is at the end of the file without reading from it; the C standard library doesn't guarantee that the EOF status is set until _after_ you've tried to read past the end of the file. I don't know, but I suspect that may be why python doesn't support querying files for EOF status - the fact that EOF can be false when you've read all the data in the file is a source of confusion to lots of C programmers. It looks like ruby internally buffers the stream itself, which is how come it can support this. According to the docs: "Note that IO#eof? reads data to a input buffer." http://www.ruby-doc.org/core/classes/IO.html#M002309 I'd imagine that's inefficient in a lot of cases; and I don't think it provides much benefit. What's the hardship in checking the return values of your IO calls? Or iterating over the file, which is a more elegant solution in many cases. -- http://mail.python.org/mailman/listinfo/python-list
