On Wed, Mar 18, 2009 at 5:51 PM, Jim Garrison <j...@acm.org> wrote: > Jim Garrison wrote: >> >> Luis Zarrabeitia wrote: >>> >>> On Tuesday 17 March 2009 06:04:36 pm Jim Garrison wrote: >>> with open(filename, "rb") as f: >>> for buf in iter(lambda: f.read(1000),''): >>> do_something(buf) >> >> This is the most pythonic solution yet. >> >> Thanks to all the responders who took time to ponder this seemingly >> trivial question. I learned a lot about the Python mind-set. > > I just tried the code as given above and it results in an infinite loop. > > Since f.read() returns a byte string when in binary mode, the sentinel > has to be b''. Is there a value that will compare equal to both '' and b''? > > It's a shame the iter(o,sentinel) builtin does the > comparison itself, instead of being defined as iter(callable,callable) > where the second argument implements the termination test and returns a > boolean. This would seem to add much more generality... is > it worthy of a PEP?
Just before you start writing a PEP, take a look at `takewhile' function in `itertools' module. ;) > > -- > http://mail.python.org/mailman/listinfo/python-list > -- Wbr, Andrii V. Mishkovskyi. He's got a heart of a little child, and he keeps it in a jar on his desk. -- http://mail.python.org/mailman/listinfo/python-list
