[Python-ideas] Python 3.x and bytes
Ethan Furman
ethan at stoneleaf.us
Wed May 18 22:10:15 CEST 2011
As those who have to work with byte strings know, when retrieving a
single character from a byte string, what you get back is not a byte
string, but an int -- a rather important distinction from unicode
strings (str).
This has the frustrating side-effect of
b'abc'[2] == b'c'
being False.
It is far too late to change that particular behavior of the byte string
(returning int's, that is) -- however, it may not be too late for a
non-backwards-incompatible change:
have the bytes class' __eq__ method be modified so that it
1) checks to see if the bytes instance is length 1
2) checks to see if
a) the other object is an int, and
b) 0 <= other_obj < 256
3) if 1 and 2, make the comparison between the int and its
single element instead of returning NotImplemented?
This makes sense to me -- after all, the bytes class is an array of ints
in range(256); it is a special case, but doesn't feel any more special
than passing an int into bytes() giving a string of that many null
bytes; and it would get rid of the, in my opinion ugly, idiom of
some_var[i:i+1] == b'd'
It would also not require a new literal syntax.
Thoughts?
~Ethan~
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