The curses module exposes the ACS_* line-drawing codes, but not their WACS_* counterparts.
X/Open Curses defines both: ACS_* are chtype characters, limited to the terminal's 8-bit alternate character set, and WACS_* are the same characters as cchar_t values for the wide-character interfaces.
Now that curses has complexchar cells (gh-151757), the WACS_* constants can be exposed as complexchar objects, added to the module by initscr() and newterm() like the ACS_* codes.
win.border(curses.WACS_VLINE, curses.WACS_VLINE, curses.WACS_HLINE, curses.WACS_HLINE)