[Python-Dev] Pathlib enhancements - acceptable inputs and outputs for __fspath__ and os.fspath()
random832 at fastmail.com
Mon Apr 11 14:18:08 EDT 2016
On Mon, Apr 11, 2016, at 13:36, Brett Cannon wrote:
> How about we take something from the "explicit is better than implicit"
> playbook and add a keyword argument to os.fspath() to allow bytes to pass
Except, we already know how to convert a bytes-path into a str (and vice
versa) with sys.getfilesystemencoding and surrogateescape. So why not
just have the argument specify what return type is desired?
def fspath(path, *, want_bytes=False):
if isinstance(path, (bytes, str)):
ppath = path
ppath = path.__fspath__()
if isinstance(ppath, str):
return ppath.encode(...) if want_bytes else ppath
elif isinstance(ppath, bytes):
return ppath if want_bytes else ppath.decode(...)
This way the posix os module can call the function and have the bytes
value already prepared for it to pass to the real open() syscall.
You could even add the same thing in other places, e.g. os.path.join
(defaulting to if the first argument is a bytes).
More information about the Python-Dev