proposal: another file iterator

[Paul Rubin]

I find pretty often that I want to loop through characters in a file:

while True:
c = f.read(1)
if not c: break
...

or sometimes of some other blocksize instead of 1. It would sure
be easier to say something like:

for c in f.iterbytes(): ...

or

for c in f.iterbytes(blocksize): ...

this isn't anything terribly advanced but just seems like a matter of
having the built-in types keep up with language features. The current
built-in iterator (for line in file: ...) is useful for text files but
can potentially read strings of unbounded size, so it's inadvisable for
arbitrary files.

Does anyone else like this idea?

 

[Raymond Hettinger]

I find pretty often that I want to loop through characters in a file:

while True:
c = f.read(1)
if not c: break
...

or sometimes of some other blocksize instead of 1. It would sure
be easier to say something like:

for c in f.iterbytes(): ...

or

for c in f.iterbytes(blocksize): ...

this isn't anything terribly advanced but just seems like a matter of
having the built-in types keep up with language features. The current
built-in iterator (for line in file: ...) is useful for text files but
can potentially read strings of unbounded size, so it's inadvisable for
arbitrary files.

Does anyone else like this idea?

+1 It would be nice to see this replace the old API where you had to
test for an empty return value.


FWIW, I've seen it expressed using other tools:

for c in iter(partial(somefile.read, blocksize), ''):
. . .

Raymond