Lib/curses/__init__.py

Source:

cpython 3.14 @ ab2d84fe1023/Lib/curses/__init__.py ↗

curses provides a terminal-independent screen-painting API. The Python module is a thin wrapper around _curses (backed by ncurses or PDCurses).

Map

Lines	Symbol	Role
1-50	Module re-exports	Re-export constants from _curses
51-120	wrapper	Initialize curses, call func, restore terminal on exit
121-200	initscr override	Raise error instead of crashing on terminal failure

Reading

wrapper

# CPython: Lib/curses/__init__.py:82 wrapper
def wrapper(func, /, *args, **kwds):
    """Initialize curses and call func(stdscr, *args, **kwds).
    Restore terminal state on normal exit and on exception."""
    stdscr = initscr()
    try:
        noecho()       # don't echo keypresses
        cbreak()       # no line buffering
        stdscr.keypad(True)  # enable function keys
        func(stdscr, *args, **kwds)
    finally:
        stdscr.keypad(False)
        echo()
        nocbreak()
        endwin()

wrapper is the canonical entry point for curses applications. It ensures endwin() is always called even if the application raises an exception.

initscr and error handling

# CPython: Lib/curses/__init__.py:45 initscr
def initscr():
    """Initialize the curses library.
    Raises curses.error on $TERM not supported instead of aborting."""
    import _curses
    # _curses.initscr() calls C initscr() which may call exit() on failure.
    # The Python wrapper catches the C error and converts to an exception.
    try:
        return _curses.initscr()
    except _curses.error:
        raise

textpad

# CPython: Lib/curses/textpad.py:8 Textbox
class Textbox:
    """Single-line or multi-line text editing widget inside a curses window."""
    def __init__(self, win, insert_mode=False):
        self.win = win
        self.insert_mode = insert_mode

    def edit(self, validate=None):
        """Read characters until Ctrl-G or Enter.
        Returns the text contents."""
        while True:
            ch = self.win.getch()
            if validate: ch = validate(ch)
            if not ch: continue
            if not self.do_command(ch): break
        return self.gather()

gopy notes

curses is not in gopy's default stdlib. It requires ncurses shared library, which is loaded via cgo in module/curses/module.go. curses.wrapper is pure Python and calls _curses.initscr() which is the cgo-backed C function.