Add index entries for open(): 	buffer size, I/O 	I/O control, buffering 	line-buffered I/O 	unbuffered I/O
Add index entries for open():
	buffer size, I/O
	I/O control, buffering
	line-buffered I/O
	unbuffered I/O

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator