[issue14156] argparse.FileType for '-' doesn't work for a mode of 'rb'

[hongweipeng]

Change by hongweipeng <hongweichen8888 at sina.com>:


----------
pull_requests: +8577
stage: test needed -> patch review

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue14156>
_______________________________________