curses --- 字元儲存格顯示的終端處理

原始碼：Lib/curses

---

The curses module provides an interface to the curses library, the de-facto standard for portable advanced terminal handling.

While curses is most widely used in the Unix environment, versions are available for Windows, DOS, and possibly other systems as well. This extension module is designed to match the API of ncurses, an open-source curses library hosted on Linux and the BSD variants of Unix.

可用性: not Android, not iOS, not WASI.

此模組在行動平台或 WebAssembly 平台上不支援。

This is an optional module. If it is missing from your copy of CPython, look for documentation from your distributor (that is, whoever provided Python to you). If you are the distributor, see 可選模組的需求.

可用性: Unix.

備註

Whenever the documentation mentions a character it can be specified as an integer, a one-character Unicode string or a one-byte byte string.

Whenever the documentation mentions a character string it can be specified as a Unicode string or a byte string.

也參考

curses.ascii 模組

Utilities for working with ASCII characters, regardless of your locale settings.

curses.panel 模組

A panel stack extension that adds depth to curses windows.

curses.textpad 模組

Editable text widget for curses supporting Emacs-like bindings.

Curses Programming with Python

Tutorial material on using curses with Python, by Andrew Kuchling and Eric Raymond.

函式

curses 模組定義了以下例外：

exception curses.error

Exception raised when a curses library function returns an error.

備註

Whenever x or y arguments to a function or a method are optional, they default to the current cursor location. Whenever attr is optional, it defaults to A_NORMAL.

curses 模組定義了以下函式：

curses.assume_default_colors(fg, bg, /)

Allow use of default values for colors on terminals supporting this feature. Use this to support transparency in your application.

• Assign terminal default foreground/background colors to color number -1. So init_pair(x, COLOR_RED, -1) will initialize pair x as red on default background and init_pair(x, -1, COLOR_BLUE) will initialize pair x as default foreground on blue.

• Change the definition of the color-pair 0 to (fg, bg).

在 3.14 版被加入.

curses.baudrate()

Return the output speed of the terminal in bits per second. On software terminal emulators it will have a fixed high value. Included for historical reasons; in former times, it was used to write output loops for time delays and occasionally to change interfaces depending on the line speed.

curses.beep()

Emit a short attention sound.

curses.can_change_color()

Return True or False, depending on whether the programmer can change the colors displayed by the terminal.

curses.cbreak()

Enter cbreak mode. In cbreak mode (sometimes called "rare" mode) normal tty line buffering is turned off and characters are available to be read one by one. However, unlike raw mode, special characters (interrupt, quit, suspend, and flow control) retain their effects on the tty driver and calling program. Calling first raw() then cbreak() leaves the terminal in cbreak mode.

curses.color_content(color_number)

Return the intensity of the red, green, and blue (RGB) components in the color color_number, which must be between 0 and COLORS - 1. Return a 3-tuple, containing the R,G,B values for the given color, which will be between 0 (no component) and 1000 (maximum amount of component).

curses.color_pair(pair_number)

Return the attribute value for displaying text in the specified color pair. Only the first 256 color pairs are supported. This attribute value can be combined with A_STANDOUT, A_REVERSE, and the other A_* attributes. pair_number() is the counterpart to this function.

curses.curs_set(visibility)

Set the cursor state. visibility can be set to 0, 1, or 2, for invisible, normal, or very visible. If the terminal supports the visibility requested, return the previous cursor state; otherwise raise an exception. On many terminals, the "visible" mode is an underline cursor and the "very visible" mode is a block cursor.

curses.def_prog_mode()

Save the current terminal mode as the "program" mode, the mode when the running program is using curses. (Its counterpart is the "shell" mode, for when the program is not in curses.) Subsequent calls to reset_prog_mode() will restore this mode.

curses.def_shell_mode()

Save the current terminal mode as the "shell" mode, the mode when the running program is not using curses. (Its counterpart is the "program" mode, when the program is using curses capabilities.) Subsequent calls to reset_shell_mode() will restore this mode.

curses.delay_output(ms)

Insert an ms millisecond pause in output.

curses.doupdate()

Update the physical screen. The curses library keeps two data structures, one representing the current physical screen contents and a virtual screen representing the desired next state. The doupdate() ground updates the physical screen to match the virtual screen.

The virtual screen may be updated by a noutrefresh() call after write operations such as addstr() have been performed on a window. The normal refresh() call is simply noutrefresh() followed by doupdate(); if you have to update multiple windows, you can speed performance and perhaps reduce screen flicker by issuing noutrefresh() calls on all windows, followed by a single doupdate().

curses.echo()

Enter echo mode. In echo mode, each character input is echoed to the screen as it is entered.

curses.endwin()

De-initialize the library, and return terminal to normal status.

curses.erasechar()

Return the user's current erase character as a one-byte bytes object. Under Unix operating systems this is a property of the controlling tty of the curses program, and is not set by the curses library itself.

curses.filter()

The filter() routine, if used, must be called before initscr() is called. The effect is that, during those calls, LINES is set to 1; the capabilities clear, cup, cud, cud1, cuu1, cuu, vpa are disabled; and the home string is set to the value of cr. The effect is that the cursor is confined to the current line, and so are screen updates. This may be used for enabling character-at-a-time line editing without touching the rest of the screen.

curses.flash()

Flash the screen. That is, change it to reverse-video and then change it back in a short interval. Some people prefer such as 'visible bell' to the audible attention signal produced by beep().

curses.flushinp()

Flush all input buffers. This throws away any typeahead that has been typed by the user and has not yet been processed by the program.

curses.getmouse()

After getch() returns KEY_MOUSE to signal a mouse event, this method should be called to retrieve the queued mouse event, represented as a 5-tuple (id, x, y, z, bstate). id is an ID value used to distinguish multiple devices, and x, y, z are the event's coordinates. (z is currently unused.) bstate is an integer value whose bits will be set to indicate the type of event, and will be the bitwise OR of one or more of the following constants, where n is the button number from 1 to 5: BUTTONn_PRESSED, BUTTONn_RELEASED, BUTTONn_CLICKED, BUTTONn_DOUBLE_CLICKED, BUTTONn_TRIPLE_CLICKED, BUTTON_SHIFT, BUTTON_CTRL, BUTTON_ALT.

在 3.10 版的變更: The BUTTON5_* constants are now exposed if they are provided by the underlying curses library.

curses.getsyx()

Return the current coordinates of the virtual screen cursor as a tuple (y, x). If leaveok is currently True, then return (-1, -1).

curses.getwin(file)

Read window related data stored in the file by an earlier window.putwin() call. The routine then creates and initializes a new window using that data, returning the new window object.

curses.has_colors()

Return True if the terminal can display colors; otherwise, return False.

curses.has_extended_color_support()

Return True if the module supports extended colors; otherwise, return False. Extended color support allows more than 256 color pairs for terminals that support more than 16 colors (e.g. xterm-256color).

Extended color support requires ncurses version 6.1 or later.

在 3.10 版被加入.

curses.has_ic()

Return True if the terminal has insert- and delete-character capabilities. This function is included for historical reasons only, as all modern software terminal emulators have such capabilities.

curses.has_il()

Return True if the terminal has insert- and delete-line capabilities, or can simulate them using scrolling regions. This function is included for historical reasons only, as all modern software terminal emulators have such capabilities.

curses.has_key(ch)

Take a key value ch, and return True if the current terminal type recognizes a key with that value.

curses.halfdelay(tenths)

Used for half-delay mode, which is similar to cbreak mode in that characters typed by the user are immediately available to the program. However, after blocking for tenths tenths of seconds, raise an exception if nothing has been typed. The value of tenths must be a number between 1 and 255. Use nocbreak() to leave half-delay mode.

curses.init_color(color_number, r, g, b)

Change the definition of a color, taking the number of the color to be changed followed by three RGB values (for the amounts of red, green, and blue components). The value of color_number must be between 0 and COLORS - 1. Each of r, g, b, must be a value between 0 and 1000. When init_color() is used, all occurrences of that color on the screen immediately change to the new definition. This function is a no-op on most terminals; it is active only if can_change_color() returns True.

curses.init_pair(pair_number, fg, bg)

Change the definition of a color-pair. It takes three arguments: the number of the color-pair to be changed, the foreground color number, and the background color number. The value of pair_number must be between 1 and COLOR_PAIRS - 1 (the 0 color pair can only be changed by use_default_colors() and assume_default_colors()). The value of fg and bg arguments must be between 0 and COLORS - 1, or, after calling use_default_colors() or assume_default_colors(), -1. If the color-pair was previously initialized, the screen is refreshed and all occurrences of that color-pair are changed to the new definition.

curses.initscr()

Initialize the library. Return a window object which represents the whole screen.

備註

If there is an error opening the terminal, the underlying curses library may cause the interpreter to exit.

curses.is_term_resized(nlines, ncols)

Return True if resize_term() would modify the window structure, False otherwise.

curses.isendwin()

Return True if endwin() has been called (that is, the curses library has been deinitialized).

curses.keyname(k)

Return the name of the key numbered k as a bytes object. The name of a key generating printable ASCII character is the key's character. The name of a control-key combination is a two-byte bytes object consisting of a caret (b'^') followed by the corresponding printable ASCII character. The name of an alt-key combination (128--255) is a bytes object consisting of the prefix b'M-' followed by the name of the corresponding ASCII character.

curses.killchar()

Return the user's current line kill character as a one-byte bytes object. Under Unix operating systems this is a property of the controlling tty of the curses program, and is not set by the curses library itself.

curses.longname()

Return a bytes object containing the terminfo long name field describing the current terminal. The maximum length of a verbose description is 128 characters. It is defined only after the call to initscr().

curses.meta(flag)

If flag is True, allow 8-bit characters to be input. If flag is False, allow only 7-bit chars.

curses.mouseinterval(interval)

Set the maximum time in milliseconds that can elapse between press and release events in order for them to be recognized as a click, and return the previous interval value. The default value is 200 milliseconds, or one fifth of a second.

curses.mousemask(mousemask)

Set the mouse events to be reported, and return a tuple (availmask, oldmask). availmask indicates which of the specified mouse events can be reported; on complete failure it returns 0. oldmask is the previous value of the given window's mouse event mask. If this function is never called, no mouse events are ever reported.

curses.napms(ms)

Sleep for ms milliseconds.

curses.newpad(nlines, ncols)

Create and return a pointer to a new pad data structure with the given number of lines and columns. Return a pad as a window object.

A pad is like a window, except that it is not restricted by the screen size, and is not necessarily associated with a particular part of the screen. Pads can be used when a large window is needed, and only a part of the window will be on the screen at one time. Automatic refreshes of pads (such as from scrolling or echoing of input) do not occur. The refresh() and noutrefresh() methods of a pad require 6 arguments to specify the part of the pad to be displayed and the location on the screen to be used for the display. The arguments are pminrow, pmincol, sminrow, smincol, smaxrow, smaxcol; the p arguments refer to the upper left corner of the pad region to be displayed and the s arguments define a clipping box on the screen within which the pad region is to be displayed.

curses.newwin(nlines, ncols)

curses.newwin(nlines, ncols, begin_y, begin_x)

Return a new window, whose left-upper corner is at (begin_y, begin_x), and whose height/width is nlines/ncols.

By default, the window will extend from the specified position to the lower right corner of the screen.

curses.nl()

Enter newline mode. This mode translates the return key into newline on input, and translates newline into return and line-feed on output. Newline mode is initially on.

curses.nocbreak()

Leave cbreak mode. Return to normal "cooked" mode with line buffering.

curses.noecho()

Leave echo mode. Echoing of input characters is turned off.

curses.nonl()

Leave newline mode. Disable translation of return into newline on input, and disable low-level translation of newline into newline/return on output (but this does not change the behavior of addch('\n'), which always does the equivalent of return and line feed on the virtual screen). With translation off, curses can sometimes speed up vertical motion a little; also, it will be able to detect the return key on input.

curses.noqiflush()

When the noqiflush() routine is used, normal flush of input and output queues associated with the INTR, QUIT and SUSP characters will not be done. You may want to call noqiflush() in a signal handler if you want output to continue as though the interrupt had not occurred, after the handler exits.

curses.noraw()

Leave raw mode. Return to normal "cooked" mode with line buffering.

curses.pair_content(pair_number)

Return a tuple (fg, bg) containing the colors for the requested color pair. The value of pair_number must be between 0 and COLOR_PAIRS - 1.

curses.pair_number(attr)

Return the number of the color-pair set by the attribute value attr. color_pair() is the counterpart to this function.

curses.putp(str)

Equivalent to tputs(str, 1, putchar); emit the value of a specified terminfo capability for the current terminal. Note that the output of putp() always goes to standard output.

curses.qiflush([flag])

If flag is False, the effect is the same as calling noqiflush(). If flag is True, or no argument is provided, the queues will be flushed when these control characters are read.

curses.raw()

Enter raw mode. In raw mode, normal line buffering and processing of interrupt, quit, suspend, and flow control keys are turned off; characters are presented to curses input functions one by one.

curses.reset_prog_mode()

Restore the terminal to "program" mode, as previously saved by def_prog_mode().

curses.reset_shell_mode()

Restore the terminal to "shell" mode, as previously saved by def_shell_mode().

curses.resetty()

Restore the state of the terminal modes to what it was at the last call to savetty().

curses.resize_term(nlines, ncols)

Backend function used by resizeterm(), performing most of the work; when resizing the windows, resize_term() blank-fills the areas that are extended. The calling application should fill in these areas with appropriate data. The resize_term() function attempts to resize all windows. However, due to the calling convention of pads, it is not possible to resize these without additional interaction with the application.

curses.resizeterm(nlines, ncols)

Resize the standard and current windows to the specified dimensions, and adjusts other bookkeeping data used by the curses library that record the window dimensions (in particular the SIGWINCH handler).

curses.savetty()

Save the current state of the terminal modes in a buffer, usable by resetty().

curses.get_escdelay()

Retrieves the value set by set_escdelay().

在 3.9 版被加入.

curses.set_escdelay(ms)

Sets the number of milliseconds to wait after reading an escape character, to distinguish between an individual escape character entered on the keyboard from escape sequences sent by cursor and function keys.

在 3.9 版被加入.

curses.get_tabsize()

Retrieves the value set by set_tabsize().

在 3.9 版被加入.

curses.set_tabsize(size)

Sets the number of columns used by the curses library when converting a tab character to spaces as it adds the tab to a window.

在 3.9 版被加入.

curses.setsyx(y, x)

Set the virtual screen cursor to y, x. If y and x are both -1, then leaveok is set True.

curses.setupterm(term=None, fd=-1)

Initialize the terminal. term is a string giving the terminal name, or None; if omitted or None, the value of the TERM environment variable will be used. fd is the file descriptor to which any initialization sequences will be sent; if not supplied or -1, the file descriptor for sys.stdout will be used.

curses.start_color()

Must be called if the programmer wants to use colors, and before any other color manipulation routine is called. It is good practice to call this routine right after initscr().

start_color() initializes eight basic colors (black, red, green, yellow, blue, magenta, cyan, and white), and two global variables in the curses module, COLORS and COLOR_PAIRS, containing the maximum number of colors and color-pairs the terminal can support. It also restores the colors on the terminal to the values they had when the terminal was just turned on.

curses.termattrs()

Return a logical OR of all video attributes supported by the terminal. This information is useful when a curses program needs complete control over the appearance of the screen.

curses.termname()

Return the value of the environment variable TERM, as a bytes object, truncated to 14 characters.

curses.tigetflag(capname)

Return the value of the Boolean capability corresponding to the terminfo capability name capname as an integer. Return the value -1 if capname is not a Boolean capability, or 0 if it is canceled or absent from the terminal description.

curses.tigetnum(capname)

Return the value of the numeric capability corresponding to the terminfo capability name capname as an integer. Return the value -2 if capname is not a numeric capability, or -1 if it is canceled or absent from the terminal description.

curses.tigetstr(capname)

Return the value of the string capability corresponding to the terminfo capability name capname as a bytes object. Return None if capname is not a terminfo "string capability", or is canceled or absent from the terminal description.

curses.tparm(str[, ...])

Instantiate the bytes object str with the supplied parameters, where str should be a parameterized string obtained from the terminfo database. E.g. tparm(tigetstr("cup"), 5, 3) could result in b'\033[6;4H', the exact result depending on terminal type.

curses.typeahead(fd)

Specify that the file descriptor fd be used for typeahead checking. If fd is -1, then no typeahead checking is done.

The curses library does "line-breakout optimization" by looking for typeahead periodically while updating the screen. If input is found, and it is coming from a tty, the current update is postponed until refresh or doupdate is called again, allowing faster response to commands typed in advance. This function allows specifying a different file descriptor for typeahead checking.

curses.unctrl(ch)

Return a bytes object which is a printable representation of the character ch. Control characters are represented as a caret followed by the character, for example as b'^C'. Printing characters are left as they are.

curses.ungetch(ch)

Push ch so the next getch() will return it.

備註

Only one ch can be pushed before getch() is called.

curses.update_lines_cols()

Update the LINES and COLS module variables. Useful for detecting manual screen resize.

在 3.5 版被加入.

curses.unget_wch(ch)

Push ch so the next get_wch() will return it.

備註

Only one ch can be pushed before get_wch() is called.

在 3.3 版被加入.

curses.ungetmouse(id, x, y, z, bstate)

Push a KEY_MOUSE event onto the input queue, associating the given state data with it.

curses.use_env(flag)

If used, this function should be called before initscr() or newterm are called. When flag is False, the values of lines and columns specified in the terminfo database will be used, even if environment variables LINES and COLUMNS (used by default) are set, or if curses is running in a window (in which case default behavior would be to use the window size if LINES and COLUMNS are not set).

curses.use_default_colors()

Equivalent to assume_default_colors(-1, -1).

curses.wrapper(func, /, *args, **kwargs)

Initialize curses and call another callable object, func, which should be the rest of your curses-using application. If the application raises an exception, this function will restore the terminal to a sane state before re-raising the exception and generating a traceback. The callable object func is then passed the main window 'stdscr' as its first argument, followed by any other arguments passed to wrapper(). Before calling func, wrapper() turns on cbreak mode, turns off echo, enables the terminal keypad, and initializes colors if the terminal has color support. On exit (whether normally or by exception) it restores cooked mode, turns on echo, and disables the terminal keypad.

Window Objects

class curses.window

Window objects, as returned by initscr() and newwin() above, have the following methods and attributes:

window.addch(ch[, attr])

window.addch(y, x, ch[, attr])

Paint character ch at (y, x) with attributes attr, overwriting any character previously painted at that location. By default, the character position and attributes are the current settings for the window object.

備註

Writing outside the window, subwindow, or pad raises a curses.error. Attempting to write to the lower right corner of a window, subwindow, or pad will cause an exception to be raised after the character is printed.

window.addnstr(str, n[, attr])

window.addnstr(y, x, str, n[, attr])

Paint at most n characters of the character string str at (y, x) with attributes attr, overwriting anything previously on the display.

window.addstr(str[, attr])

window.addstr(y, x, str[, attr])

Paint the character string str at (y, x) with attributes attr, overwriting anything previously on the display.

備註

• Writing outside the window, subwindow, or pad raises curses.error. Attempting to write to the lower right corner of a window, subwindow, or pad will cause an exception to be raised after the string is printed.

• A bug in ncurses, the backend for this Python module, can cause SegFaults when resizing windows. This is fixed in ncurses-6.1-20190511. If you are stuck with an earlier ncurses, you can avoid triggering this if you do not call addstr() with a str that has embedded newlines. Instead, call addstr() separately for each line.

window.attroff(attr)

Remove attribute attr from the "background" set applied to all writes to the current window.

window.attron(attr)

Add attribute attr to the "background" set applied to all writes to the current window.

window.attrset(attr)

Set the "background" set of attributes to attr. This set is initially 0 (no attributes).

window.bkgd(ch[, attr])

Set the background property of the window to the character ch, with attributes attr. The change is then applied to every character position in that window:

• The attribute of every character in the window is changed to the new background attribute.

• Wherever the former background character appears, it is changed to the new background character.

window.bkgdset(ch[, attr])

Set the window's background. A window's background consists of a character and any combination of attributes. The attribute part of the background is combined (OR'ed) with all non-blank characters that are written into the window. Both the character and attribute parts of the background are combined with the blank characters. The background becomes a property of the character and moves with the character through any scrolling and insert/delete line/character operations.

window.border([ls[, rs[, ts[, bs[, tl[, tr[, bl[, br]]]]]]]])

Draw a border around the edges of the window. Each parameter specifies the character to use for a specific part of the border; see the table below for more details.

備註

A 0 value for any parameter will cause the default character to be used for that parameter. Keyword parameters can not be used. The defaults are listed in this table:

參數	描述	預設值
ls	Left side	ACS_VLINE
rs	Right side	ACS_VLINE
ts	Top	ACS_HLINE
bs	Bottom	ACS_HLINE
tl	Upper-left corner	ACS_ULCORNER
tr	Upper-right corner	ACS_URCORNER
bl	Bottom-left corner	ACS_LLCORNER
br	Bottom-right corner	ACS_LRCORNER

window.box([vertch, horch])

Similar to border(), but both ls and rs are vertch and both ts and bs are horch. The default corner characters are always used by this function.

window.chgat(attr)

window.chgat(num, attr)

window.chgat(y, x, attr)

window.chgat(y, x, num, attr)

Set the attributes of num characters at the current cursor position, or at position (y, x) if supplied. If num is not given or is -1, the attribute will be set on all the characters to the end of the line. This function moves cursor to position (y, x) if supplied. The changed line will be touched using the touchline() method so that the contents will be redisplayed by the next window refresh.

window.clear()

Like erase(), but also cause the whole window to be repainted upon next call to refresh().

window.clearok(flag)

If flag is True, the next call to refresh() will clear the window completely.

window.clrtobot()

Erase from cursor to the end of the window: all lines below the cursor are deleted, and then the equivalent of clrtoeol() is performed.

window.clrtoeol()

Erase from cursor to the end of the line.

window.cursyncup()

Update the current cursor position of all the ancestors of the window to reflect the current cursor position of the window.

window.delch([y, x])

Delete any character at (y, x).

window.deleteln()

Delete the line under the cursor. All following lines are moved up by one line.

window.derwin(begin_y, begin_x)

window.derwin(nlines, ncols, begin_y, begin_x)

An abbreviation for "derive window", derwin() is the same as calling subwin(), except that begin_y and begin_x are relative to the origin of the window, rather than relative to the entire screen. Return a window object for the derived window.

window.echochar(ch[, attr])

Add character ch with attribute attr, and immediately call refresh() on the window.

window.enclose(y, x)

Test whether the given pair of screen-relative character-cell coordinates are enclosed by the given window, returning True or False. It is useful for determining what subset of the screen windows enclose the location of a mouse event.

在 3.10 版的變更: Previously it returned 1 or 0 instead of True or False.

window.encoding

Encoding used to encode method arguments (Unicode strings and characters). The encoding attribute is inherited from the parent window when a subwindow is created, for example with window.subwin(). By default, current locale encoding is used (see locale.getencoding()).

在 3.3 版被加入.

window.erase()

清除視窗。

window.getbegyx()

回傳左上角的座標 (y, x)。

window.getbkgd()

回傳給定視窗目前的背景字元/屬性對。

window.getch([y, x])

Get a character. Note that the integer returned does not have to be in ASCII range: function keys, keypad keys and so on are represented by numbers higher than 255. In no-delay mode, return -1 if there is no input, otherwise wait until a key is pressed.

window.get_wch([y, x])

Get a wide character. Return a character for most keys, or an integer for function keys, keypad keys, and other special keys. In no-delay mode, raise an exception if there is no input.

在 3.3 版被加入.

window.getkey([y, x])

Get a character, returning a string instead of an integer, as getch() does. Function keys, keypad keys and other special keys return a multibyte string containing the key name. In no-delay mode, raise an exception if there is no input.

window.getmaxyx()

回傳視窗的高度和寬度的元組 (y, x)。

window.getparyx()

Return the beginning coordinates of this window relative to its parent window as a tuple (y, x). Return (-1, -1) if this window has no parent.

window.getstr()

window.getstr(n)

window.getstr(y, x)

window.getstr(y, x, n)

Read a bytes object from the user, with primitive line editing capacity. The maximum value for n is 2047.

在 3.14 版的變更: The maximum value for n was increased from 1023 to 2047.

window.getyx()

Return a tuple (y, x) of current cursor position relative to the window's upper-left corner.

window.hline(ch, n)

window.hline(y, x, ch, n)

Display a horizontal line starting at (y, x) with length n consisting of the character