curses — Terminal handling for character-cell displays¶Source code: 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.
Availability: not Android, not iOS, not WASI.
This module is not supported on mobile platforms or WebAssembly platforms.
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 Requirements for optional modules.
Availability: Unix.
Note
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.
See also
curses.asciiUtilities for working with ASCII characters, regardless of your locale settings.
curses.panelA panel stack extension that adds depth to curses windows.
curses.textpadEditable text widget for curses supporting Emacs-like bindings.
Tutorial material on using curses with Python, by Andrew Kuchling and Eric Raymond.
The module curses defines the following exception:
Exception raised when a curses library function returns an error.
Note
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.
The module curses defines the following functions:
Initialize the library. Return a window object which represents the whole screen.
See setupterm() for a caveat about calling it before this function.
Note
If there is an error opening the terminal, the underlying curses library may cause the interpreter to exit.
De-initialize the library, and return terminal to normal status.
Return True if endwin() has been called (that is, the curses library has
been deinitialized).
Initialize a new terminal in addition to the one initialized by
initscr(),
and return a screen for it.
This allows a program to drive more than one terminal.
type is the terminal name, as in setupterm();
if None, the value of the TERM environment variable is used.
fd and infd are the output and input files for the terminal:
either a file object or a file descriptor.
They default to sys.stdout and sys.stdin.
The new screen becomes the current one.
Use set_term() to switch between screens.
See setupterm() for a caveat about calling it before this function.
Added in version 3.16.0a0 (unreleased).
Return a new screen
that can be used to call functions that affect global state
before initscr() or newterm() is called.
Availability: if the underlying curses library provides new_prescr().
Added in version 3.16.0a0 (unreleased).
Make screen, a screen returned by
newterm(), the current terminal,
and return the previously current screen.
Returns None if the previous screen was the one created by
initscr().
Added in version 3.16.0a0 (unreleased).
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.
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.
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.
Restore the terminal to “program” mode, as previously saved by
def_prog_mode().
Restore the terminal to “shell” mode, as previously saved by
def_shell_mode().
Restore the state of the terminal modes to what it was at the last call to
savetty().
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.
Return the current coordinates of the virtual screen cursor as a tuple
(y, x). If leaveok is currently True, then return (-1, -1).
Set the virtual screen cursor to y, x. If y and x are both -1, then
leaveok is set True.
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() function 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().
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.
Leave cbreak mode. Return to normal “cooked” mode with line buffering.
Enter echo mode. In echo mode, each character input is echoed to the screen as it is entered.
Leave echo mode. Echoing of input characters is turned off.
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.
Leave raw mode. Return to normal “cooked” mode with line buffering.
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.
If flag is True, allow 8-bit characters to be input. If
flag is False, allow only 7-bit chars.
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.
If flag is False, the effect is the same as calling 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.
If flag is True, pressing an interrupt key (interrupt, break, or quit)
will flush all output in the terminal driver queue. If flag is False,
no flushing is done.
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.
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.
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.
Return True if cbreak mode (see cbreak()) is enabled,
False otherwise.
Availability: ncurses 6.5 or later.
Added in version 3.16.0a0 (unreleased).
Return True if echo mode (see echo()) is enabled,
False otherwise.
Availability: ncurses 6.5 or later.
Added in version 3.16.0a0 (unreleased).
Push ch so the next getch() or get_wch() will
return it.
ch may be an integer (a key code or character code), a byte, or a string of
length 1. A one-character string is pushed like unget_wch(); on a
narrow build it must encode to a single byte.
Note
Only one ch can be pushed before getch() is called.
Changed in version 3.16.0a0 (unreleased): A one-character string argument is no longer required to encode to a single byte, except on a narrow build.
Push ch so the next get_wch() will return it.
Note
Only one ch can be pushed before get_wch() is called.
Added in version 3.3.
Changed in version 3.16.0a0 (unreleased): Also available on a narrow build, where ch must encode to a single byte (an 8-bit locale).
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.
Take a key value ch, and return True if the current terminal type recognizes
a key with that value.
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.
Raise a ValueError if k is negative.
Define an escape sequence definition, a string, as a key that generates
the key code keycode, so that curses interprets it like one of the
keys predefined in the terminal database.
If definition is None, any existing binding for keycode is removed.
If keycode is zero or negative, any existing binding for definition is
removed.
Added in version 3.16.0a0 (unreleased).
Return the key code bound to the escape sequence definition, a string,
0 if no key code is bound to it, or -1 if definition is a prefix
of a longer bound sequence (and so is ambiguous).
Added in version 3.16.0a0 (unreleased).
Enable (if enable is true) or disable (otherwise) interpretation of the
key code keycode. Unlike window.keypad(), this affects a single
key code rather than all of them.
Added in version 3.16.0a0 (unreleased).
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.
Changed in version 3.10: The BUTTON5_* constants are now exposed if they are provided by the
underlying curses library.
Push a KEY_MOUSE event onto the input queue, associating the given
state data with it.
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 mouse event mask. If this function is never called, no mouse
events are ever reported.
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 166 milliseconds, or one sixth of a second. Use a negative interval to obtain the interval value without changing it.
Return True if the mouse driver has been successfully initialized.
Availability: if the underlying curses library provides has_mouse().
Added in version 3.16.0a0 (unreleased).
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.
Return True if the terminal can display colors; otherwise, return False.
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 (for example, xterm-256color).
Extended color support requires ncurses version 6.1 or later.
Added in version 3.10.
Return True or False, depending on whether the programmer can change the colors
displayed by the terminal.
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.
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). Raise an
exception if the color is not supported.
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.
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.
Return the attribute value for displaying text in the specified color pair.
Only color pairs that fit in the color-pair field of the returned value can
be represented (usually the first 256); a larger pair_number raises
OverflowError rather than being silently masked to a different pair.
Use color_set() or attr_set() to display higher
pairs. This attribute value can be combined with A_STANDOUT,
A_REVERSE, and the other A_* attributes.
pair_number() is the counterpart to this function.
Return the number of the color-pair set by the attribute value attr.
color_pair() is the counterpart to this function.
Equivalent to assume_default_colors(-1, -1).
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).
This is an ncurses extension.
Added in version 3.14.
Allocate a color pair for foreground color fg and background color bg, and return its number. If a color pair for the same combination of colors already exists, return its number. Otherwise allocate a new color pair and return its number.
This function is only available if Python was built against a wide-character
version of the underlying curses library with extended-color support (see
has_extended_color_support()).
Added in version 3.16.0a0 (unreleased).
Free the color pair pair_number, which must have been allocated by
alloc_pair(). The pair must not be in use.
This function is only available if Python was built against a wide-character
version of the underlying curses library with extended-color support (see
has_extended_color_support()).
Added in version 3.16.0a0 (unreleased).
Return the number of a color pair for foreground color fg and background
color bg, or -1 if no color pair for this combination of colors has
been allocated.
This function is only available if Python was built against a wide-character
version of the underlying curses library with extended-color support (see
has_extended_color_support()).
Added in version 3.16.0a0 (unreleased).
Discard all color-pair definitions, releasing the color pairs allocated by
init_pair() and alloc_pair().
This function is only available if Python was built against a wide-character
version of the underlying curses library with extended-color support (see
has_extended_color_support()).
Added in version 3.16.0a0 (unreleased).
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.
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.
The following functions manage soft-label keys, a row of labels displayed
along the bottom line of the screen, typically used to label a row of function
keys. slk_init() must be called before initscr() or
newterm(); it takes one screen line away from the standard window for the
labels.
Reserve a screen line for the soft labels and choose their layout. fmt
selects the arrangement: 0 for 3-2-3 (eight labels), 1 for 4-4
(eight labels). Where the underlying curses library supports them, 2
gives 4-4-4 (twelve labels) and 3 gives 4-4-4 with an index line.
Must be called before initscr() or newterm().
Added in version 3.16.0a0 (unreleased).
Set the text of soft label number labnum, in the range 1 through 8
(or 12 in a twelve-label layout). justify controls how label is
placed within the label: 0 for left, 1 for centered, 2 for right.
Added in version 3.16.0a0 (unreleased).
Return the current text of soft label number labnum, justified as it was set, or an empty string if it has no label.
Added in version 3.16.0a0 (unreleased).
Update the soft labels on the physical screen, like
refresh() for a window.
Added in version 3.16.0a0 (unreleased).
Update the soft labels on the virtual screen, like
window.noutrefresh(). Use it together with doupdate() to batch
screen updates.
Added in version 3.16.0a0 (unreleased).
Remove the soft labels from the screen.
Added in version 3.16.0a0 (unreleased).
Restore the soft labels to the screen after a slk_clear().
Added in version 3.16.0a0 (unreleased).
Force all the soft labels to be redrawn by the next slk_refresh() or
slk_noutrefresh().
Added in version 3.16.0a0 (unreleased).
Add, remove, or set the attributes used to display the soft labels, given as
packed A_* attributes.
Added in version 3.16.0a0 (unreleased).
Return the current attributes of the soft labels as packed A_*
attributes. Availability depends on the underlying curses library.
Added in version 3.16.0a0 (unreleased).
Turn the given attributes on or off without affecting any others. Like the
attr_* window methods, these work with the
WA_* attributes rather than packed A_*
attributes.
Added in version 3.16.0a0 (unreleased).
Set the attributes and color pair of the soft labels. attr is given as WA_* attributes and pair as a color pair number.
Added in version 3.16.0a0 (unreleased).
Set the color pair of the soft labels to color pair number pair.
Added in version 3.16.0a0 (unreleased).
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. The file argument must be a file object opened for
reading in binary mode.
Write the current contents of the virtual screen to filename, which may be
a string or a path-like object. The file can later be read by
scr_restore(), scr_init() or scr_set(). This is the
whole-screen counterpart of window.putwin().
Added in version 3.16.0a0 (unreleased).
Set the virtual screen to the contents of filename, which must have been
written by scr_dump(). The next call to doupdate() or
window.refresh() restores the screen to those contents.
Added in version 3.16.0a0 (unreleased).
Initialize the assumed contents of the terminal from filename, which must
have been written by scr_dump(). Use it when the terminal already
displays those contents, for example after another program has drawn the
screen, so that curses does not redraw what is already there.
Added in version 3.16.0a0 (unreleased).
Use filename, which must have been written by scr_dump(), as both
the virtual screen and the assumed terminal contents. This combines the
effects of scr_restore() and scr_init().
Added in version 3.16.0a0 (unreleased).
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.
Return the user’s current erase character as a raw byte, a bytes
object of length 1. See also erasewchar().
Return the user’s current erase character as a one-character str.
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.
Added in version 3.16.0a0 (unreleased).
Return the user’s current line kill character as a raw byte, a bytes
object of length 1. See also killwchar().
Return the user’s current line kill character as a one-character str.
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.
Added in version 3.16.0a0 (unreleased).
Return the value of the environment variable TERM, as a bytes object,
truncated to 14 characters.
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().
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.
Like termattrs(), but return the attributes as WA_* values rather than A_* values.
Added in version 3.16.0a0 (unreleased).
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.
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.
Emit a short attention sound.
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).
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.
Return True if resize_term() would modify the window structure,
False otherwise.
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.
Raise a curses.error if the terminal could not be found or its
terminfo database entry could not be read. If the terminal has already
been initialized, this function has no effect.
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.
setupterm() (or initscr()) must be called first.
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.
setupterm() (or initscr()) must be called first.
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.
setupterm() (or initscr()) must be called first.
Instantiate the bytes object str with the supplied parameters, where str should
be a parameterized string obtained from the terminfo database. For example,
tparm(tigetstr("cup"), 5, 3) could result in b'\033[6;4H', the exact
result depending on terminal type. Up to nine integer parameters may be supplied.
setupterm() (or initscr()) must be called first.
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.
setupterm() (or initscr()) must be called first.
Return a bytes object which is a printable representation of the character ch.
ch cannot be a character that does not fit in a single byte; use
wunctrl() for those.
Return a string which is a printable representation of the character ch;
any attributes and color pair are ignored.
ASCII control characters are represented as a caret followed by a character,
for example as '^C'. Printing characters, including non-ASCII characters
printable in the locale, are left as they are. The representation of other
characters is defined by the underlying curses library.
Added in version 3.16.0a0 (unreleased).
The filter() routine, if used, must be called before initscr() is
called. The effect is that, during the initialization, 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.
Undo the effect of a previous filter() call.
Like filter(), it must be called before initscr() (or
newterm()) so that the next initialization uses the full screen
again.
Availability: if the underlying curses library provides nofilter().
Added in version 3.16.0a0 (unreleased).
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).
Retrieves the value set by set_escdelay().
Added in version 3.9.
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.
Added in version 3.9.
Retrieves the value set by set_tabsize().
Added in version 3.9.
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.
Added in version 3.9.
Sleep for ms milliseconds.
Insert an ms millisecond pause in output.
Window objects, as returned by initscr() and newwin() above, have
the following methods and attributes:
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.
ch may be a single character, optionally followed by combining characters, that together occupy one character cell.
Note
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.
Changed in version 3.16.0a0 (unreleased): A character may now be given as a string of a base character followed
by combining characters, instead of only a single character, or as a
complexchar cell.
Paint the character string str at (y, x) with attributes
attr, overwriting anything previously on the display.
str may also be a complexstr, in which case each cell carries its
own attributes and color pair, so attr must not be given. A
complexstr obtained from in_wchstr() is written back
unchanged.
Note
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, could cause
segfaults when resizing windows. This was fixed in ncurses-6.1-20190511.
If you are stuck with an earlier ncurses, you can avoid triggering it by
not calling addstr() with a str that has embedded newlines;
instead, call addstr() separately for each line.
Changed in version 3.16.0a0 (unreleased): str may now also be a complexstr, as described above.
Paint at most n characters of the character string str at
(y, x) with attributes
attr, overwriting anything previously on the display.
Changed in version 3.16.0a0 (unreleased): str may now also be a complexstr; see addstr().
Add character ch with attribute attr, and immediately call refresh()
on the window.
Changed in version 3.16.0a0 (unreleased): Wide and combining characters, and complexchar cells, are now
accepted.
Insert character ch with attributes attr before the character under the
cursor, or at (y, x) if specified. All characters to the right of the
cursor are shifted one position right, with the rightmost character on the
line being lost. The cursor position does not change.
Changed in version 3.16.0a0 (unreleased): Wide and combining characters, and complexchar cells, are now
accepted.
Insert a character string (as many characters as will fit on the line) before the character under the cursor. All characters to the right of the cursor are shifted right, with the rightmost characters on the line being lost. The cursor position does not change (after moving to y, x, if specified).
str may also be a complexstr, in which case each cell carries its
own attributes and color pair, so attr must not be given.
Changed in version 3.16.0a0 (unreleased): str may now also be a complexstr, as described above.
Insert a character string (as many characters as will fit on the line) before the character under the cursor, up to n characters. If n is zero or negative, the entire string is inserted. All characters to the right of the cursor are shifted right, with the rightmost characters on the line being lost. The cursor position does not change (after moving to y, x, if specified).
Changed in version 3.16.0a0 (unreleased): str may now also be a complexstr; see insstr().
Delete the character under the cursor, or at (y, x) if specified. All
characters to the right on the same line are shifted one position left.
Delete the line under the cursor. All following lines are moved up by one line.
Insert a blank line under the cursor. All following lines are moved down by one line.
Insert nlines lines into the specified window above the current line. The nlines bottom lines are lost. For negative nlines, delete nlines lines starting with the one under the cursor, and move the remaining lines up. The bottom nlines lines are cleared. The current cursor position remains the same.
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.
A multibyte character is returned as its encoded bytes one at a time; use
get_wch() to read it as a single character.
Get a wide character. Return a character for most keys, or an integer for
function keys, keypad keys, and other special keys. Unlike getch(), an
ordinary key is returned as a one-character str.
In no-delay mode, raise an exception if there is no input.
Added in version 3.3.
Changed in version 3.16.0a0 (unreleased): Also available on a narrow build, where only a character representable as a single byte (an 8-bit locale) can be returned.
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.
Read a bytes object from the user, with primitive line editing capacity.
At most n characters are read;
n defaults to and cannot exceed 2047.
A multibyte character is returned as its encoded bytes; use get_wstr()
to read the input as a str.
Changed in version 3.14: The maximum value for n was increased from 1023 to 2047.
Read a string from the user, with primitive line editing capacity.
Unlike getstr(), it can return characters that are not representable in
the window’s encoding.
At most n characters are read; n defaults to and cannot exceed 2047.
Added in version 3.16.0a0 (unreleased).
Return the character at the given position in the window.
The bottom 8 bits are the character proper and the upper bits are the attributes;
extract them with the A_CHARTEXT and A_ATTRIBUTES bit-masks,
and the color pair with pair_number().
The character byte is the locale-encoded byte of the cell’s character,
consistent with instr().
It cannot represent a cell holding combining characters, a character that does
not fit in a single byte, or a color pair outside the color_pair()
range; use in_wch() for those, which returns it as a complexchar.
Return the complex character at the given position in the window as a
complexchar. Unlike inch(), the returned object carries the
cell’s text (a spacing character optionally followed by combining characters)
together with its attributes and color pair.
Added in version 3.16.0a0 (unreleased).
Return a bytes object of characters, extracted from the window starting at the
current cursor position, or at y, x if specified, and stopping at the end
of the line. Attributes and color information are stripped
from the characters. If n is specified, instr() returns a string
at most n characters long (exclusive of the trailing NUL).
The maximum value for n is 2047.
A character not representable in the window’s encoding cannot be returned;
use in_wstr() for those.
Changed in version 3.14: The maximum value for n was increased from 1023 to 2047.
Return a string of characters, extracted from the window starting at the
current cursor position, or at y, x if specified. Unlike instr(),
it can return characters that are not representable in the window’s encoding.
Attributes and color information are stripped from the characters. The
maximum value for n is 2047.
Added in version 3.16.0a0 (unreleased).
Return a complexstr of the styled cells extracted from the window
starting at the current cursor position, or at y, x if specified, and
stopping at the end of the line. This is the variant of instr() and
in_wstr() that keeps each cell’s attributes and color pair (those
methods strip the rendition). If n is specified, at most n cells are
returned. The maximum value for n is 2047.
The result can be written back unchanged with addstr() (a read and a
re-write is a round-trip that preserves every cell’s rendition).
Added in version 3.16.0a0 (unreleased).
Remove attribute attr from the “background” set applied to all writes to the current window.
Add attribute attr to the “background” set applied to all writes to the current window.
Set the “background” set of attributes to attr. This set is initially
0 (no attributes).
Return the window’s current rendition as a (attrs, pair) tuple,
where attrs is the set of attributes and pair is the color pair number.
Unlike attron() and friends, which take packed A_* attributes,
this method and the other attr_* methods work with the
WA_* attributes and keep the color pair as a
separate number, which lets them use color pairs that do not fit alongside
the attributes in a single value.
Added in version 3.16.0a0 (unreleased).
Set the window’s rendition to the attributes attr and the color pair pair.
Added in version 3.16.0a0 (unreleased).
Turn on the attributes attr without affecting any others.
Added in version 3.16.0a0 (unreleased).
Turn off the attributes attr without affecting any others.
Added in version 3.16.0a0 (unreleased).
Set the window’s color pair to pair, leaving the other attributes unchanged.
Added in version 3.16.0a0 (unreleased).
Return the window’s current attributes.
Added in version 3.16.0a0 (unreleased).
Turn on attribute A_STANDOUT.
Turn off the standout attribute. On some terminals this has the side effect of turning off all attributes.
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.
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.
Changed in version 3.16.0a0 (unreleased): Wide and combining characters, and complexchar cells, are now
accepted.
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.
Changed in version 3.16.0a0 (unreleased): Wide and combining characters, and complexchar cells, are now
accepted.
Return the given window’s current background character/attribute pair.
Its components can be extracted like those of inch().
It cannot represent a background set with a wide character or with a color
pair outside the color_pair() range; use getbkgrnd() for those.
Return the given window’s current background as a complexchar.
Unlike getbkgd(), the returned object carries the background character
together with its attributes and color pair, and the color pair is not limited
to the value that fits in a color_pair().
Added in version 3.16.0a0 (unreleased).
Clear the window.
Like erase(), but also cause the whole window to be repainted upon next
call to refresh().
Erase from cursor to the end of the window: all lines below the cursor are
deleted, and then the equivalent of clrtoeol() is performed.
Erase from cursor to the end of the line.
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.
Note
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:
Parameter |
Description |
Default value |
|---|---|---|
ls |
Left side |
|
rs |
Right side |
|
ts |
Top |
|
bs |
Bottom |
|
tl |
Upper-left corner |
|
tr |
Upper-right corner |
|
bl |
Bottom-left corner |
|
br |
Bottom-right corner |
Changed in version 3.16.0a0 (unreleased): Wide and combining characters, and complexchar cells, are now
accepted. A single call cannot mix
them with integer or byte characters.
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.
Changed in version 3.16.0a0 (unreleased): Wide and combining characters, and complexchar cells, are now
accepted. A single call cannot mix
them with integer or byte characters.
Display a horizontal line starting at (y, x) with length n consisting of
the character ch with attributes attr. The line stops at the right edge
of the window if fewer than n cells are available.
Changed in version 3.16.0a0 (unreleased): Wide and combining characters, and complexchar cells, are now
accepted.
Display a vertical line starting at (y, x) with length n consisting of the
character ch with attributes attr.
Changed in version 3.16.0a0 (unreleased): Wide and combining characters, and complexchar cells, are now
accepted.
Move cursor to (new_y, new_x).
Return a tuple (y, x) of current cursor position relative to the window’s
upper-left corner.
Return a tuple (y, x) of coordinates of upper-left corner.
Return a tuple (y, x) of the height and width of the window.
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.
Return the parent window of this subwindow,
or None if this window is not a subwindow.
Added in version 3.16.0a0 (unreleased).
Return a sub-window, whose upper-left corner is at the screen-relative
coordinates (begin_y, begin_x), and whose width/height is ncols/nlines.
By default, the sub-window will extend from the specified position to the lower right corner of the window.
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.
Return a sub-pad, whose upper-left corner is at (begin_y, begin_x), and
whose width/height is ncols/nlines. The coordinates are relative to the
parent pad (unlike subwin(), which uses screen coordinates). This
method is only available for pads created with newpad().
Return a new window that is an exact duplicate of the window: it has the same
size, position, contents and attributes. Unlike a window created by
subwin() or derwin(), the duplicate is independent of the
original – it has its own cell buffer, so later changes to one do not affect
the other.
Added in version 3.16.0a0 (unreleased).
Move the window so its upper-left corner is at (new_y, new_x).
Moving the window so that any part of it would be off the screen is an error:
the window is not moved and curses.error is raised.
Move the window inside its parent window. The screen-relative parameters of the window are not changed. This routine is used to display different parts of the parent window at the same physical position on the screen.
Update the display immediately (sync actual screen with previous drawing/deleting methods).
The 6 arguments can only be specified, and are then required, when the window
is a pad created with newpad(). The additional parameters are needed to indicate what part
of the pad and screen are involved. pminrow and pmincol specify the
upper-left corner of the rectangle to be displayed in the pad. sminrow,
smincol, smaxrow, and smaxcol specify the edges of the rectangle to be
displayed on the screen. The lower-right corner of the rectangle to be
displayed in the pad is calculated from the screen coordinates, since the
rectangles must be the same size. Both rectangles must be entirely contained
within their respective structures. Negative values of pminrow, pmincol,
sminrow, or smincol are treated as if they were zero.
Mark for refresh but wait. This function updates the data structure
representing the desired state of the window, but does not force an update of
the physical screen. To accomplish that, call doupdate().
The 6 arguments can only be specified, and are then required, when the window
is a pad created with newpad(); they have the same meaning as for
refresh().
If flag is True, curses will try to use hardware line
editing facilities. Otherwise, curses will not use them.
If flag is False, curses no longer considers using the hardware insert/delete
character feature of the terminal; if flag is True, use of character insertion
and deletion is enabled. When curses is first initialized, use of character
insert/delete is enabled by default.
If flag is True, any change in the window image automatically causes the
window to be refreshed; you no longer have to call refresh() yourself.
However, it may degrade performance considerably, due to repeated calls to
wrefresh. This option is disabled by default.
If flag is True, cursor is left where it is on update, instead of being at “cursor
position.” This reduces cursor movement where possible.
If flag is False, cursor will always be at “cursor position” after an update.
Control what happens when the cursor of a window is moved off the edge of the
window or scrolling region, either as a result of a newline action on the bottom
line, or typing the last character of the last line. If flag is False, the
cursor is left on the bottom line. If flag is True, the window is scrolled up
one line. Note that in order to get the physical scrolling effect on the
terminal, it is also necessary to call idlok().
Scroll the screen or scrolling region. Scroll upward by lines lines if
lines is positive, or downward if it is negative. Scrolling has no effect
unless it has been enabled for the window with scrollok().
Set the scrolling region from line top to line bottom. All scrolling actions will take place in this region.
Return a tuple (top, bottom) of the window’s current scrolling region,
as set by setscrreg().
Added in version 3.16.0a0 (unreleased).
If flag is True, escape sequences generated by some keys (keypad, function keys)
will be interpreted by curses. If flag is False, escape sequences will be
left as is in the input stream.
If flag is True, escape sequences will not be timed out.
If flag is False, after a few milliseconds, an escape sequence will not be
interpreted, and will be left in the input stream as is.
Set blocking or non-blocking read behavior for the window. If delay is
negative, blocking read is used (which will wait indefinitely for input). If
delay is zero, then non-blocking read is used, and getch() will
return -1 if no input is waiting. If delay is positive, then
getch() will block for delay milliseconds, and return -1 if there is
still no input at the end of that time.
Overlay the window on top of destwin. The windows need not be the same size, only the overlapping region is copied. This copy is non-destructive, which means that the current background character does not overwrite the old contents of destwin.
To get fine-grained control over the copied region, the second form of
overlay() can be used. sminrow and smincol are the upper-left
coordinates of the source window, and the other variables mark a rectangle in
the destination window.
Overwrite the window on top of destwin. The windows need not be the same size, in which case only the overlapping region is copied. This copy is destructive, which means that the current background character overwrites the old contents of destwin.
To get fine-grained control over the copied region, the second form of
overwrite() can be used. sminrow and smincol are the upper-left
coordinates of the source window, the other variables mark a rectangle in the
destination window.
Pretend count lines have been changed, starting with line start. If
changed is supplied, it specifies whether the affected lines are marked as
having been changed (changed=True) or unchanged (changed=False).
Pretend the whole window has been changed, for purposes of drawing optimizations.
Touch all locations in ancestors of the window that have been changed in the window.
Touch each location in the window that has been touched in any of its ancestor
windows. This routine is called by refresh(), so it should almost never
be necessary to call it manually.
Update the current cursor position of all the ancestors of the window to reflect the current cursor position of the window.
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.
Changed in version 3.10: Previously it returned 1 or 0 instead of True or False.
Convert between window-relative and screen-relative (stdscr-relative) character-cell coordinates.
If to_screen is true, convert the window-relative coordinates y, x to screen-relative coordinates;
otherwise convert in the opposite direction.
The two coordinate systems differ when lines are reserved on the screen, for example for soft labels.
Return the converted coordinates as a (y, x) tuple, or None if they lie outside the window.
Added in version 3.16.0a0 (unreleased).
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()).
Added in version 3.3.
Write all data associated with the window into the provided file object. This
information can be later retrieved using the getwin() function.
Call func(window, *args, **kwargs) with the lock of the window held,
and return its result.
This provides automatic protection for the window
against concurrent access from another thread.
Availability: if the underlying curses library provides use_window().
Added in version 3.16.0a0 (unreleased).
Return the current value set by clearok().
Added in version 3.16.0a0 (unreleased).
Return the current value set by immedok().
Added in version 3.16.0a0 (unreleased).
Return the current value set by keypad().
Added in version 3.16.0a0 (unreleased).
Return the current value set by leaveok().
Added in version 3.16.0a0 (unreleased).
Return True if the specified line was modified since the last call to
refresh(); otherwise return False. Raise a curses.error
exception if line is not valid for the given window.
Return the current value set by nodelay().
Added in version 3.16.0a0 (unreleased).
Return the current value set by notimeout().
Added in version 3.16.0a0 (unreleased).
Return True if the window is a pad created by newpad().
Added in version 3.16.0a0 (unreleased).
Return the current value set by scrollok().
Added in version 3.16.0a0 (unreleased).
Return True if the window is a subwindow created by subwin()
or derwin().
Added in version 3.16.0a0 (unreleased).
A screen object represents a terminal initialized by newterm()
(or new_prescr()),
in addition to the default screen created by initscr().
Screen objects are returned by those functions;
they cannot be instantiated directly.
A screen is freed automatically once it is no longer referenced, either directly or through one of its windows. Each window keeps its screen alive, so a screen remains valid as long as any of its windows does.
Added in version 3.16.0a0 (unreleased).
Detach the screen’s standard window,
breaking the reference cycle between them
so the screen can be reclaimed promptly instead of waiting for a
garbage collection.
Afterwards stdscr is None
and the window it returned earlier can no longer be used.
The screen’s resources are released
once it and all its windows are no longer referenced.
Added in version 3.16.0a0 (unreleased).
The standard window of the screen,
covering the whole terminal,
or None for a screen created by new_prescr().
Call func(screen, *args, **kwargs) with the lock of the screen held,
and return its result.
This provides automatic protection for the screen
against concurrent access from another thread.
Availability: if the underlying curses library provides use_screen().
Added in version 3.16.0a0 (unreleased).
A complex character (or complexchar) is an immutable styled character cell: a spacing character optionally followed by combining characters, together with a set of attributes and a color pair.
text is the cell’s text, attr a combination of the
WA_* attributes (equivalent to the matching
A_* constants), and pair a color pair number. Unlike the packed
chtype used by inch() and the A_* methods,
the color pair is stored separately and is not limited to the value that
fits in a color_pair().
Complex characters are returned by window.in_wch() and
window.getbkgrnd(), and are accepted (along with an integer, a byte
or a string) by the character-cell methods such as window.addch(),
window.insch(), window.bkgd(), window.border(),
window.hline() and window.vline(). A complex character already
carries its own rendition, so it cannot be combined with an explicit attr
argument.
str() returns the cell’s text; two complex characters are equal when
their text, attributes and color pair all match.
The same code works on both wide- and narrow-character builds. On a narrow
build a cell holds a single character (no combining marks) that must encode to
one byte in the window’s encoding (8-bit locales only), and pair is limited
to the value that fits in a color_pair().
The attributes of the character cell (read-only).
The color pair number of the character cell (read-only).
Added in version 3.16.0a0 (unreleased).
A complex character string (or complexstr) is an immutable sequence of
styled character cells – the string counterpart of
complexchar (as str is to a single character).
If cells is a string, it is split into character cells (each a spacing character optionally followed by combining characters), and attr (a combination of the WA_* attributes) and pair (a color pair number), if given, are applied to every cell.
Otherwise cells is an iterable whose items are themselves cells, each a
complexchar or a string; each item then carries its own rendition,
and attr and pair must be omitted.
It is returned by window.in_wchstr(), and accepted by
window.addstr(), addnstr(), insstr() and
insnstr(), so a run read from a window can be written back
unchanged.
It behaves like an immutable sequence: len(s) is the number of cells,
s[i] is the i-th cell as a complexchar, slicing and
concatenation produce new complexstr instances, and iterating
yields the cells. str() returns the cells’ text joined together, and
two complex character strings are equal when their cells all match. It is
hashable.
To build or edit a run of cells, use an ordinary list of
complexchar (or strings); a complexstr is the immutable
form returned by a read.
Like complexchar, this type works on both wide- and narrow-character
builds, with the same per-cell limitations on a narrow build.
Added in version 3.16.0a0 (unreleased).
The curses module defines the following data members:
A bytes object representing the current version of the module.
A named tuple containing the three components of the ncurses library
version: major, minor, and patch. All values are integers. The
components can also be accessed by name, so curses.ncurses_version[0]
is equivalent to curses.ncurses_version.major and so on.
Availability: if the ncurses library is used.
Added in version 3.8.
The maximum number of colors the terminal can support.
It is defined only after the call to start_color().
The maximum number of color pairs the terminal can support.
It is defined only after the call to start_color().
The width of the screen, that is, the number of columns.
It is defined only after the call to initscr().
Updated by update_lines_cols(), resizeterm() and
resize_term().
The height of the screen, that is, the number of lines.
It is defined only after the call to initscr().
Updated by update_lines_cols(), resizeterm() and
resize_term().
Some constants are available to specify character cell attributes. The exact constants available are system dependent.
Attribute |
Meaning |
|---|---|
|
Alternate character set mode |
|
Blink mode |
|
Bold mode |
|
Dim mode |
|
Invisible or blank mode |
|
Italic mode |
|
Normal attribute |
|
Protected mode |
|
Reverse background and foreground colors |
|
Standout mode |
|
Underline mode |
|
Horizontal highlight |
|
Left highlight |
|
Low highlight |
|
Right highlight |
|
Top highlight |
|
Vertical highlight |
Added in version 3.7: A_ITALIC was added.
The attr_get(), attr_set(), attr_on()
and attr_off() methods use a parallel set of WA_* constants.
These have the same meaning as the corresponding A_* attributes above
(WA_BOLD like A_BOLD, and so on), but belong to the attr_t type
rather than being packed into a character. In ncurses the two sets share the
same values, but other curses implementations may give them different ones, so
use the WA_* constants with the attr_* methods. The available names are
WA_ATTRIBUTES, WA_NORMAL, WA_STANDOUT, WA_UNDERLINE,
WA_REVERSE, WA_BLINK, WA_DIM, WA_BOLD, WA_ALTCHARSET,
WA_INVIS, WA_PROTECT, WA_HORIZONTAL, WA_LEFT, WA_LOW,
WA_RIGHT, WA_TOP, WA_VERTICAL and WA_ITALIC (each available only
where the platform defines it).
Added in version 3.16.0a0 (unreleased): The WA_* constants were added.
Several constants are available to extract corresponding attributes returned by some methods.
Bit-mask |
Meaning |
|---|---|
|
Bit-mask to extract attributes |
|
Bit-mask to extract a character |
|
Bit-mask to extract color-pair field information |
Keys are referred to by integer constants with names starting with KEY_.
The exact keycaps available are system dependent.
Key constant |
Key |
|---|---|
|
Minimum key value |
|
Break key (unreliable) |
|
Down-arrow |
|
Up-arrow |
|
Left-arrow |
|
Right-arrow |
|
Home key (upward+left arrow) |
|
Backspace (unreliable) |
|
Function keys. Up to 64 function keys are supported. |
|
Value of function key n |
|
Delete line |
|
Insert line |
|
Delete character |
|
Insert char or enter insert mode |
|
Exit insert char mode |
|
Clear screen |
|
Clear to end of screen |
|
Clear to end of line |
|
Scroll 1 line forward |
|
Scroll 1 line backward (reverse) |
|
Next page |
|
Previous page |
|
Set tab |
|
Clear tab |
|
Clear all tabs |
|
Enter or send (unreliable) |
|
Soft (partial) reset (unreliable) |
|
Reset or hard reset (unreliable) |
|
|
|
Home down or bottom (lower left) |
|
Upper left of keypad |
|
Upper right of keypad |
|
Center of keypad |
|
Lower left of keypad |
|
Lower right of keypad |
|
Back tab |
|
Beg (beginning) |
|
Cancel |
|
Close |
|
Cmd (command) |
|
Copy |
|
Create |
|
End |
|
Exit |
|
Find |
|
Help |
|
Mark |
|
Message |
|
Move |
|
Next |
|
Open |
|
Options |
|
Prev (previous) |
|
Redo |
|
Ref (reference) |
|
Refresh |
|
Replace |
|
Restart |
|
Resume |
|
Save |
|
Shifted Beg (beginning) |
|
Shifted Cancel |
|
Shifted Command |
|
Shifted Copy |
|
Shifted Create |
|
Shifted Delete char |
|
Shifted Delete line |
|
Select |
|
Shifted End |
|
Shifted Clear line |
|
Shifted Exit |
|
Shifted Find |
|
Shifted Help |
|
Shifted Home |
|
Shifted Input |
|
Shifted Left arrow |
|
Shifted Message |
|
Shifted Move |
|
Shifted Next |
|
Shifted Options |
|
Shifted Prev |
|
Shifted Print |
|
Shifted Redo |
|
Shifted Replace |
|
Shifted Right arrow |
|
Shifted Resume |
|
Shifted Save |
|
Shifted Suspend |
|
Shifted Undo |
|
Suspend |
|
Undo |
|
Mouse event has occurred |
|
Terminal resize event |
|
Maximum key value |
On VT100s and their software emulations, such as X terminal emulators, there are
normally at least four function keys (KEY_F1, KEY_F2,
KEY_F3, KEY_F4) available, and the arrow keys mapped to
KEY_UP, KEY_DOWN, KEY_LEFT and KEY_RIGHT in
the obvious way. If your machine has a PC keyboard, it is safe to expect arrow
keys and twelve function keys (older PC keyboards may have only ten function
keys); also, the following keypad mappings are standard:
Keycap |
Constant |
|---|---|
Insert |
KEY_IC |
Delete |
KEY_DC |
Home |
KEY_HOME |
End |
KEY_END |
Page Up |
KEY_PPAGE |
Page Down |
KEY_NPAGE |
The following table lists characters from the alternate character set. These are inherited from the VT100 terminal, and will generally be available on software emulations such as X terminals. When there is no graphic available, curses falls back on a crude printable ASCII approximation.
Note
These are available only after initscr() has been called.
ACS code |
Meaning |
|---|---|
|
alternate name for upper-right corner |
|
solid square block |
|
board of squares |
|
alternate name for horizontal line |
|
alternate name for upper-left corner |
|
alternate name for top tee |
|
bottom tee |
|
bullet |
|
checker board (stipple) |
|
arrow pointing down |
|
degree symbol |
|
diamond |
|
greater-than-or-equal-to |
|
horizontal line |
|
lantern symbol |
|
left arrow |
|
less-than-or-equal-to |
|
lower-left corner |
|
lower-right corner |
|
left tee |
|
not-equal sign |
|
letter pi |
|
plus-or-minus sign |
|
big plus sign |
|
right arrow |
|
right tee |
|
scan line 1 |
|
scan line 3 |
|
scan line 7 |
|
scan line 9 |
|
alternate name for lower-right corner |
|
alternate name for vertical line |
|
alternate name for right tee |
|
alternate name for lower-left corner |
|
alternate name for bottom tee |
|
alternate name for left tee |
|
alternate name for crossover or big plus |
|
pound sterling |
|
top tee |
|
up arrow |
|
upper-left corner |
|
upper-right corner |
|
vertical line |
The following table lists the predefined colors:
Constant |
Color |
|---|---|
|
Black |
|
Blue |
|
Cyan (light greenish blue) |
|
Green |
|
Magenta (purplish red) |
|
Red |
|
White |
|
Yellow |
curses.textpad — Text input widget for curses programs¶The curses.textpad module provides a Textbox class that handles
elementary text editing in a curses window, supporting a set of keybindings
resembling those of Emacs (thus, also of Netscape Navigator, BBedit 6.x,
FrameMaker, and many other programs). The module also provides a
rectangle-drawing function useful for framing text boxes or for other purposes.
The module curses.textpad defines the following function:
Draw a rectangle. The first argument must be a window object; the remaining arguments are coordinates relative to that window. The second and third arguments are the y and x coordinates of the upper-left corner of the rectangle to be drawn; the fourth and fifth arguments are the y and x coordinates of the lower-right corner. The rectangle will be drawn using VT100/IBM PC forms characters on terminals that make this possible (including xterm and most other software terminal emulators). Otherwise it will be drawn with ASCII dashes, vertical bars, and plus signs.
You can instantiate a Textbox object as follows:
Return a textbox widget object. The win argument should be a curses
window object in which the textbox is to
be contained. If insert_mode is true, the textbox inserts typed
characters, shifting existing text to the right, rather than overwriting it.
The edit cursor of the textbox is initially located at the
upper-left corner of the containing window, with coordinates (0, 0).
The instance’s stripspaces flag is initially on.
Changed in version 3.16.0a0 (unreleased): Entering and reading back the full Unicode range, including combining characters, is now supported when curses is built with wide-character support.
Textbox objects have the following methods:
This is the entry point you will normally use. It accepts editing
keystrokes until one of the termination keystrokes is entered. If
validate is supplied, it must be a function. It will be called for
each keystroke entered with the keystroke as a parameter; command dispatch
is done on the result. If it returns a false value, the keystroke is
ignored. This method returns the window contents as a
string; whether blanks in the window are included is affected by the
stripspaces attribute.
Changed in version 3.16.0a0 (unreleased): validate is now called with a non-ASCII character as a string; other keystrokes are still passed as an integer.
Process a single command keystroke. Returns 1 to continue editing,
or 0 if a termination keystroke was processed. Here are the supported
special keystrokes:
Keystroke |
Action |
|---|---|
Control-A |
Go to left edge of window. |
Control-B |
Cursor left, wrapping to previous line if appropriate. |
Control-D |
Delete character under cursor. |
Control-E |
Go to right edge (stripspaces off) or end of line (stripspaces on). |
Control-F |
Cursor right, wrapping to next line when appropriate. |
Control-G |
Terminate, returning the window contents. |
Control-H |
Delete character backward. |
Control-J |
Terminate if the window is 1 line, otherwise move to the start of the next line. |
Control-K |
If line is blank, delete it, otherwise clear to end of line. |
Control-L |
Refresh screen. |
Control-N |
Cursor down; move down one line. |
Control-O |
Insert a blank line at cursor location. |
Control-P |
Cursor up; move up one line. |
Move operations do nothing if the cursor is at an edge where the movement is not possible. The following synonyms are supported where possible:
Constant |
Keystroke |
|---|---|
Control-B |
|
Control-F |
|
Control-P |
|
Control-N |
|
Control-h |
All other keystrokes are treated as a command to insert the given character and move right (with line wrapping).
Return the window contents as a string; whether blanks in the
window are included is affected by the stripspaces member.
This attribute is a flag which controls the interpretation of blanks in the window. When it is on, trailing blanks on each line are ignored; any cursor motion that would land the cursor on a trailing blank goes to the end of that line instead, and trailing blanks are stripped when the window contents are gathered.