Thecurses module provides an interface to the curses library, thede-facto standard for portable advanced terminal handling.
While curses is most widely used in the Unix environment, versions are availablefor DOS, OS/2, and possibly other systems as well. This extension module isdesigned to match the API of ncurses, an open-source curses library hosted onLinux and the BSD variants of Unix.
Note
Since version 5.4, the ncurses library decides how to interpret non-ASCII datausing thenl_langinfo function. That means that you have to calllocale.setlocale() in the application and encode Unicode stringsusing one of the system’s available encodings. This example uses thesystem’s default encoding:
importlocalelocale.setlocale(locale.LC_ALL,'')code=locale.getpreferredencoding()
Then usecode as the encoding forstr.encode() calls.
See also
TheTools/demo/ directory in the Python source distribution containssome example programs using the curses bindings provided by this module.
The modulecurses defines the following exception:
Exception raised when a curses library function returns an error.
Note
Wheneverx ory arguments to a function or a method are optional, theydefault to the current cursor location. Wheneverattr is optional, it defaultstoA_NORMAL.
The modulecurses defines the following functions:
Return the output speed of the terminal in bits per second. On softwareterminal emulators it will have a fixed high value. Included for historicalreasons; in former times, it was used to write output loops for time delays andoccasionally to change interfaces depending on the line speed.
Emit a short attention sound.
ReturnTrue orFalse, depending on whether the programmer can change the colorsdisplayed by the terminal.
Enter cbreak mode. In cbreak mode (sometimes called “rare” mode) normal ttyline buffering is turned off and characters are available to be read one by one.However, unlike raw mode, special characters (interrupt, quit, suspend, and flowcontrol) retain their effects on the tty driver and calling program. Callingfirstraw() thencbreak() leaves the terminal in cbreak mode.
Return the intensity of the red, green, and blue (RGB) components in the colorcolor_number, which must be between0 andCOLORS. A 3-tuple isreturned, containing the R,G,B values for the given color, which will be between0 (no component) and1000 (maximum amount of component).
Return the attribute value for displaying text in the specified color. Thisattribute value can be combined withA_STANDOUT,A_REVERSE,and the otherA_* attributes.pair_number() is the counterpartto this function.
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, theprevious cursor state is returned; otherwise, an exception is raised. On manyterminals, the “visible” mode is an underline cursor and the “very visible” modeis a block cursor.
Save the current terminal mode as the “program” mode, the mode when the runningprogram is using curses. (Its counterpart is the “shell” mode, for when theprogram is not in curses.) Subsequent calls toreset_prog_mode() willrestore this mode.
Save the current terminal mode as the “shell” mode, the mode when the runningprogram is not using curses. (Its counterpart is the “program” mode, when theprogram is using curses capabilities.) Subsequent calls toreset_shell_mode() will restore this mode.
Insert anms millisecond pause in output.
Update the physical screen. The curses library keeps two data structures, onerepresenting the current physical screen contents and a virtual screenrepresenting the desired next state. Thedoupdate() ground updates thephysical screen to match the virtual screen.
The virtual screen may be updated by anoutrefresh() call after writeoperations such asaddstr() have been performed on a window. The normalrefresh() call is simplynoutrefresh() followed bydoupdate();if you have to update multiple windows, you can speed performance and perhapsreduce screen flicker by issuingnoutrefresh() calls on all windows,followed by a singledoupdate().
Enter echo mode. In echo mode, each character input is echoed to the screen asit is entered.
De-initialize the library, and return terminal to normal status.
Return the user’s current erase character. Under Unix operating systems thisis a property of the controlling tty of the curses program, and is not set bythe curses library itself.
Thefilter() routine, if used, must be called beforeinitscr() iscalled. The effect is that, during those calls,LINES is set to 1; thecapabilities clear, cup, cud, cud1, cuu1, cuu, vpa are disabled; and the homestring is set to the value of cr. The effect is that the cursor is confined tothe current line, and so are screen updates. This may be used for enablingcharacter-at-a-time line editing without touching the rest of the screen.
Flash the screen. That is, change it to reverse-video and then change it backin a short interval. Some people prefer such as ‘visible bell’ to the audibleattention signal produced bybeep().
Flush all input buffers. This throws away any typeahead that has been typedby the user and has not yet been processed by the program.
Aftergetch() returnsKEY_MOUSE to signal a mouse event, thismethod should be call to retrieve the queued mouse event, represented as a5-tuple(id,x,y,z,bstate).id is an ID value used to distinguishmultiple devices, andx,y,z are the event’s coordinates. (z iscurrently unused.)bstate is an integer value whose bits will be set toindicate the type of event, and will be the bitwise OR of one or more of thefollowing constants, wheren is the button number from 1 to 4:BUTTONn_PRESSED,BUTTONn_RELEASED,BUTTONn_CLICKED,BUTTONn_DOUBLE_CLICKED,BUTTONn_TRIPLE_CLICKED,BUTTON_SHIFT,BUTTON_CTRL,BUTTON_ALT.
Return the current coordinates of the virtual screen cursor in y and x. Ifleaveok is currently true, then -1,-1 is returned.
Read window related data stored in the file by an earlierputwin() call.The routine then creates and initializes a new window using that data, returningthe new window object.
ReturnTrue if the terminal can display colors; otherwise, returnFalse.
ReturnTrue if the terminal has insert- and delete-character capabilities.This function is included for historical reasons only, as all modern softwareterminal emulators have such capabilities.
ReturnTrue if the terminal has insert- and delete-line capabilities, or cansimulate them using scrolling regions. This function is included forhistorical reasons only, as all modern software terminal emulators have suchcapabilities.
Take a key valuech, and returnTrue if the current terminal type recognizesa key with that value.
Used for half-delay mode, which is similar to cbreak mode in that characterstyped by the user are immediately available to the program. However, afterblocking fortenths tenths of seconds, an exception is raised if nothing hasbeen typed. The value oftenths must be a number between1 and255. Usenocbreak() to leave half-delay mode.
Change the definition of a color, taking the number of the color to be changedfollowed by three RGB values (for the amounts of red, green, and bluecomponents). The value ofcolor_number must be between0 andCOLORS. Each ofr,g,b, must be a value between0 and1000. Wheninit_color() is used, all occurrences of that color on thescreen immediately change to the new definition. This function is a no-op onmost terminals; it is active only ifcan_change_color() returns1.
Change the definition of a color-pair. It takes three arguments: the number ofthe color-pair to be changed, the foreground color number, and the backgroundcolor number. The value ofpair_number must be between1 andCOLOR_PAIRS-1 (the0 color pair is wired to white on black and cannotbe changed). The value offg andbg arguments must be between0 andCOLORS. If the color-pair was previously initialized, the screen isrefreshed and all occurrences of that color-pair are changed to the newdefinition.
Initialize the library. Return aWindowObject which represents thewhole screen.
Note
If there is an error opening the terminal, the underlying curses library maycause the interpreter to exit.
ReturnTrue ifresize_term() would modify the window structure,False otherwise.
ReturnTrue ifendwin() has been called (that is, the curses library hasbeen deinitialized).
Return the name of the key numberedk. The name of a key generating printableASCII character is the key’s character. The name of a control-key combinationis a two-character string consisting of a caret followed by the correspondingprintable ASCII character. The name of an alt-key combination (128-255) is astring consisting of the prefix ‘M-‘ followed by the name of the correspondingASCII character.
Return the user’s current line kill character. Under Unix operating systemsthis is a property of the controlling tty of the curses program, and is not setby the curses library itself.
Return a string containing the terminfo long name field describing the currentterminal. The maximum length of a verbose description is 128 characters. It isdefined only after the call toinitscr().
Ifyes is 1, allow 8-bit characters to be input. Ifyes is 0, allow only7-bit chars.
Set the maximum time in milliseconds that can elapse between press and releaseevents in order for them to be recognized as a click, and return the previousinterval value. The default value is 200 msec, or one fifth of a second.
Set the mouse events to be reported, and return a tuple(availmask,oldmask).availmask indicates which of the specified mouse events can bereported; on complete failure it returns 0.oldmask is the previous value ofthe given window’s mouse event mask. If this function is never called, no mouseevents are ever reported.
Sleep forms milliseconds.
Create and return a pointer to a new pad data structure with the given numberof lines and columns. A pad is returned as a window object.
A pad is like a window, except that it is not restricted by the screen size, andis not necessarily associated with a particular part of the screen. Pads can beused when a large window is needed, and only a part of the window will be on thescreen at one time. Automatic refreshes of pads (such as from scrolling orechoing of input) do not occur. Therefresh() andnoutrefresh()methods of a pad require 6 arguments to specify the part of the pad to bedisplayed and the location on the screen to be used for the display. Thearguments arepminrow,pmincol,sminrow,smincol,smaxrow,smaxcol; theparguments refer to the upper left corner of the pad region to be displayed andthes arguments define a clipping box on the screen within which the pad regionis to be displayed.
Return a new window, whose left-upper corner is at(begin_y,begin_x), andwhose height/width isnlines/ncols.
By default, the window will extend from the specified position to the lowerright corner of the screen.
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 isinitially on.
Leave cbreak mode. Return to normal “cooked” mode with line buffering.
Leave echo mode. Echoing of input characters is turned off.
Leave newline mode. Disable translation of return into newline on input, anddisable low-level translation of newline into newline/return on output (but thisdoes not change the behavior ofaddch('\n'), which always does theequivalent of return and line feed on the virtual screen). With translationoff, curses can sometimes speed up vertical motion a little; also, it will beable to detect the return key on input.
When thenoqiflush() routine is used, normal flush of input and output queuesassociated with the INTR, QUIT and SUSP characters will not be done. You maywant to callnoqiflush() in a signal handler if you want output tocontinue as though the interrupt had not occurred, after the handler exits.
Leave raw mode. Return to normal “cooked” mode with line buffering.
Return a tuple(fg,bg) containing the colors for the requested color pair.The value ofpair_number must be between1 andCOLOR_PAIRS-1.
Return the number of the color-pair set by the attribute valueattr.color_pair() is the counterpart to this function.
Equivalent totputs(str,1,putchar); emit the value of a specifiedterminfo capability for the current terminal. Note that the output ofputp()always goes to standard output.
Ifflag isFalse, the effect is the same as callingnoqiflush(). Ifflag isTrue, or no argument is provided, the queues will be flushed whenthese control characters are read.
Enter raw mode. In raw mode, normal line buffering and processing ofinterrupt, quit, suspend, and flow control keys are turned off; characters arepresented to curses input functions one by one.
Restore the terminal to “program” mode, as previously saved bydef_prog_mode().
Restore the terminal to “shell” mode, as previously saved bydef_shell_mode().
Restore the state of the terminal modes to what it was at the last call tosavetty().
Backend function used byresizeterm(), performing most of the work;when resizing the windows,resize_term() blank-fills the areas that areextended. The calling application should fill in these areas withappropriate data. Theresize_term() function attempts to resize allwindows. However, due to the calling convention of pads, it is not possibleto resize these without additional interaction with the application.
Resize the standard and current windows to the specified dimensions, andadjusts other bookkeeping data used by the curses library that record thewindow dimensions (in particular the SIGWINCH handler).
Set the virtual screen cursor toy,x. Ify andx are both -1, thenleaveok is set.
Initialize the terminal.termstr is a string giving the terminal name; ifomitted, the value of theTERM environment variable will be used.fd is thefile descriptor to which any initialization sequences will be sent; if notsupplied, the file descriptor forsys.stdout will be used.
Must be called if the programmer wants to use colors, and before any other colormanipulation routine is called. It is good practice to call this routine rightafterinitscr().
start_color() initializes eight basic colors (black, red, green, yellow,blue, magenta, cyan, and white), and two global variables in thecursesmodule,COLORS andCOLOR_PAIRS, containing the maximum numberof colors and color-pairs the terminal can support. It also restores the colorson the terminal to the values they had when the terminal was just turned on.
Return a logical OR of all video attributes supported by the terminal. Thisinformation is useful when a curses program needs complete control over theappearance of the screen.
Return the value of the environment variableTERM, truncated to 14 characters.
Return the value of the Boolean capability corresponding to the terminfocapability namecapname. The value-1 is returned ifcapname is not aBoolean capability, or0 if it is canceled or absent from the terminaldescription.
Return the value of the numeric capability corresponding to the terminfocapability namecapname. The value-2 is returned ifcapname is not anumeric capability, or-1 if it is canceled or absent from the terminaldescription.
Return the value of the string capability corresponding to the terminfocapability namecapname.None is returned ifcapname is not a stringcapability, or is canceled or absent from the terminal description.
Instantiate the stringstr with the supplied parameters, wherestr shouldbe a parameterized string obtained from the terminfo database. E.g.tparm(tigetstr("cup"),5,3) could result inb'\033[6;4H', the exactresult depending on terminal type.
Specify that the file descriptorfd be used for typeahead checking. Iffdis-1, then no typeahead checking is done.
The curses library does “line-breakout optimization” by looking for typeaheadperiodically while updating the screen. If input is found, and it is comingfrom a tty, the current update is postponed until refresh or doupdate is calledagain, allowing faster response to commands typed in advance. This functionallows specifying a different file descriptor for typeahead checking.
Return a string which is a printable representation of the characterch.Control characters are displayed as a caret followed by the character, forexample as^C. Printing characters are left as they are.
Pushch so the nextgetch() will return it.
Note
Only onech can be pushed beforegetch() is called.
Pushch so the nextget_wch() will return it.
Note
Only onech can be pushed beforeget_wch() is called.
New in version 3.3.
Push aKEY_MOUSE event onto the input queue, associating the givenstate data with it.
If used, this function should be called beforeinitscr() or newterm arecalled. Whenflag isFalse, the values of lines and columns specified in theterminfo database will be used, even if environment variablesLINESandCOLUMNS (used by default) are set, or if curses is running in awindow (in which case default behavior would be to use the window size ifLINES andCOLUMNS are not set).
Allow use of default values for colors on terminals supporting this feature. Usethis to support transparency in your application. The default color is assignedto the color number -1. After calling this function,init_pair(x,curses.COLOR_RED,-1) initializes, for instance, color pairx to a redforeground color on the default background.
Initialize curses and call another callable object,func, which should be therest of your curses-using application. If the application raises an exception,this function will restore the terminal to a sane state before re-raising theexception and generating a traceback. The callable objectfunc is then passedthe main window ‘stdscr’ as its first argument, followed by any other argumentspassed towrapper(). Before callingfunc,wrapper() turns oncbreak mode, turns off echo, enables the terminal keypad, and initializes colorsif 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, as returned byinitscr() andnewwin() above, havethe following methods and attributes:
Note
Acharacter means a C character (an ASCII code), rather than a Pythoncharacter (a string of length 1). (This note is true whenever thedocumentation mentions a character.) The built-inord() is handy forconveying strings to codes.
Paint characterch at(y,x) with attributesattr, overwriting anycharacter previously painter at that location. By default, the characterposition and attributes are the current settings for the window object.
Paint at mostn characters of the stringstr at(y,x) with attributesattr, overwriting anything previously on the display.
Paint the stringstr at(y,x) with attributesattr, overwritinganything previously on the display.
Remove attributeattr from the “background” set applied to all writes to thecurrent window.
Add attributeattr from the “background” set applied to all writes to thecurrent window.
Set the “background” set of attributes toattr. This set is initially 0 (noattributes).
Set the background property of the window to the characterch, withattributesattr. The change is then applied to every character position inthat window:
Set the window’s background. A window’s background consists of a character andany combination of attributes. The attribute part of the background is combined(OR’ed) with all non-blank characters that are written into the window. Boththe character and attribute parts of the background are combined with the blankcharacters. The background becomes a property of the character and moves withthe character through any scrolling and insert/delete line/character operations.
Draw a border around the edges of the window. Each parameter specifies thecharacter to use for a specific part of the border; see the table below for moredetails. The characters can be specified as integers or as one-characterstrings.
Note
A0 value for any parameter will cause the default character to be used forthat parameter. Keyword parameters cannot be used. The defaults are listedin this table:
| Parameter | Description | Default value |
|---|---|---|
| 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 |
Similar toborder(), but bothls andrs arevertch and bothts andbs arehorch. The default corner characters are always used by this function.
Set the attributes ofnum characters at the current cursor position, or atposition(y,x) if supplied. If no value ofnum is given ornum = -1,the attribute will be set on all the characters to the end of the line. Thisfunction does not move the cursor. The changed line will be touched using thetouchline() method so that the contents will be redisplayed by the nextwindow refresh.
Likeerase(), but also cause the whole window to be repainted upon nextcall torefresh().
Erase from cursor to the end of the window: all lines below the cursor aredeleted, and then the equivalent ofclrtoeol() is performed.
Erase from cursor to the end of the line.
Update the current cursor position of all the ancestors of the window toreflect the current cursor position of the window.
Delete any character at(y,x).
Delete the line under the cursor. All following lines are moved up by one line.
An abbreviation for “derive window”,derwin() is the same as callingsubwin(), except thatbegin_y andbegin_x are relative to the originof the window, rather than relative to the entire screen. Return a windowobject for the derived window.
Add characterch with attributeattr, and immediately callrefresh()on the window.
Test whether the given pair of screen-relative character-cell coordinates areenclosed by the given window, returningTrue orFalse. It is useful fordetermining what subset of the screen windows enclose the location of a mouseevent.
Encoding used to encode method arguments (Unicode strings and characters).The encoding attribute is inherited from the parent window when a subwindowis created, for example withwindow.subwin(). By default, the localeencoding is used (seelocale.getpreferredencoding()).
New in version 3.3.
Clear the window.
Return a tuple(y,x) of co-ordinates of upper-left corner.
Return the given window’s current background character/attribute pair.
Get a character. Note that the integer returned doesnot have to be in ASCIIrange: function keys, keypad keys and so on return numbers higher than 256. Inno-delay mode, -1 is returned if there is no input, elsegetch() waitsuntil a key is pressed.
Get a wide character. Return a character for most keys, or an integer forfunction keys, keypad keys, and other special keys.
New in version 3.3.
Get a character, returning a string instead of an integer, asgetch()does. Function keys, keypad keys and other special keys return a multibytestring containing the key name. In no-delay mode, an exception is raised ifthere is no input.
Return a tuple(y,x) of the height and width of the window.
Return the beginning coordinates of this window relative to its parent windowinto two integer variables y and x. Return-1,-1 if this window has noparent.
Read a string from the user, with primitive line editing capacity.
Return a tuple(y,x) of current cursor position relative to the window’supper-left corner.
Display a horizontal line starting at(y,x) with lengthn consisting ofthe characterch.
Ifflag isFalse, curses no longer considers using the hardware insert/deletecharacter feature of the terminal; ifflag isTrue, use of character insertionand deletion is enabled. When curses is first initialized, use of characterinsert/delete is enabled by default.
If called withyes equal to 1,curses will try and use hardware lineediting facilities. Otherwise, line insertion/deletion are disabled.
Ifflag isTrue, any change in the window image automatically causes thewindow to be refreshed; you no longer have to callrefresh() yourself.However, it may degrade performance considerably, due to repeated calls towrefresh. This option is disabled by default.
Return the character at the given position in the window. The bottom 8 bits arethe character proper, and upper bits are the attributes.
Paint characterch at(y,x) with attributesattr, moving the line frompositionx right by one character.
Insertnlines lines into the specified window above the current line. Thenlines bottom lines are lost. For negativenlines, deletenlines linesstarting with the one under the cursor, and move the remaining lines up. Thebottomnlines lines are cleared. The current cursor position remains thesame.
Insert a blank line under the cursor. All following lines are moved down by oneline.
Insert a character string (as many characters as will fit on the line) beforethe character under the cursor, up ton characters. Ifn is zero ornegative, the entire string is inserted. All characters to the right of thecursor are shifted right, with the rightmost characters on the line being lost.The cursor position does not change (after moving toy,x, if specified).
Insert a character string (as many characters as will fit on the line) beforethe character under the cursor. All characters to the right of the cursor areshifted right, with the rightmost characters on the line being lost. The cursorposition does not change (after moving toy,x, if specified).
Return a string of characters, extracted from the window starting at thecurrent cursor position, or aty,x if specified. Attributes are strippedfrom the characters. Ifn is specified,instr() returns a stringat mostn characters long (exclusive of the trailing NUL).
ReturnTrue if the specified line was modified since the last call torefresh(); otherwise returnFalse. Raise acurses.errorexception ifline is not valid for the given window.
ReturnTrue if the specified window was modified since the last call torefresh(); otherwise returnFalse.
Ifyes is 1, escape sequences generated by some keys (keypad, function keys)will be interpreted bycurses. Ifyes is 0, escape sequences will beleft as is in the input stream.
Ifyes is 1, cursor is left where it is on update, instead of being at “cursorposition.” This reduces cursor movement where possible. If possible the cursorwill be made invisible.
Ifyes is 0, cursor will always be at “cursor position” after an update.
Move cursor to(new_y,new_x).
Move the window inside its parent window. The screen-relative parameters ofthe window are not changed. This routine is used to display different parts ofthe parent window at the same physical position on the screen.
Move the window so its upper-left corner is at(new_y,new_x).
Ifyes is1, escape sequences will not be timed out.
Ifyes is0, after a few milliseconds, an escape sequence will not beinterpreted, and will be left in the input stream as is.
Mark for refresh but wait. This function updates the data structurerepresenting the desired state of the window, but does not force an update ofthe physical screen. To accomplish that, calldoupdate().
Overlay the window on top ofdestwin. The windows need not be the same size,only the overlapping region is copied. This copy is non-destructive, which meansthat the current background character does not overwrite the old contents ofdestwin.
To get fine-grained control over the copied region, the second form ofoverlay() can be used.sminrow andsmincol are the upper-leftcoordinates of the source window, and the other variables mark a rectangle inthe destination window.
Overwrite the window on top ofdestwin. 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 ofdestwin.
To get fine-grained control over the copied region, the second form ofoverwrite() can be used.sminrow andsmincol are the upper-leftcoordinates of the source window, the other variables mark a rectangle in thedestination window.
Write all data associated with the window into the provided file object. Thisinformation can be later retrieved using thegetwin() function.
Indicate that thenum screen lines, starting at linebeg, are corrupted andshould be completely redrawn on the nextrefresh() call.
Touch the entire window, causing it to be completely redrawn on the nextrefresh() call.
Update the display immediately (sync actual screen with previousdrawing/deleting methods).
The 6 optional arguments can only be specified when the window is a pad createdwithnewpad(). The additional parameters are needed to indicate what partof the pad and screen are involved.pminrow andpmincol specify the upperleft-hand corner of the rectangle to be displayed in the pad.sminrow,smincol,smaxrow, andsmaxcol specify the edges of the rectangle to bedisplayed on the screen. The lower right-hand corner of the rectangle to bedisplayed in the pad is calculated from the screen coordinates, since therectangles must be the same size. Both rectangles must be entirely containedwithin their respective structures. Negative values ofpminrow,pmincol,sminrow, orsmincol are treated as if they were zero.
Reallocate storage for a curses window to adjust its dimensions to thespecified values. If either dimension is larger than the current values, thewindow’s data is filled with blanks that have the current backgroundrendition (as set bybkgdset()) merged into them.
Scroll the screen or scrolling region upward bylines lines.
Control what happens when the cursor of a window is moved off the edge of thewindow or scrolling region, either as a result of a newline action on the bottomline, or typing the last character of the last line. Ifflag is false, thecursor is left on the bottom line. Ifflag is true, the window is scrolled upone line. Note that in order to get the physical scrolling effect on theterminal, it is also necessary to callidlok().
Set the scrolling region from linetop to linebottom. All scrolling actionswill take place in this region.
Turn off the standout attribute. On some terminals this has the side effect ofturning off all attributes.
Turn on attributeA_STANDOUT.
Return a sub-window, whose upper-left corner is at(begin_y,begin_x), andwhose width/height isncols/nlines.
Return a sub-window, whose upper-left corner is at(begin_y,begin_x), andwhose width/height isncols/nlines.
By default, the sub-window will extend from the specified position to the lowerright corner of the window.
Touch each location in the window that has been touched in any of its ancestorwindows. This routine is called byrefresh(), so it should almost neverbe necessary to call it manually.
If called withflag set toTrue, thensyncup() is called automaticallywhenever there is a change in the window.
Touch all locations in ancestors of the window that have been changed in thewindow.
Set blocking or non-blocking read behavior for the window. Ifdelay isnegative, blocking read is used (which will wait indefinitely for input). Ifdelay is zero, then non-blocking read is used, and -1 will be returned bygetch() if no input is waiting. Ifdelay is positive, thengetch() will block fordelay milliseconds, and return -1 if there isstill no input at the end of that time.
Pretendcount lines have been changed, starting with linestart. Ifchanged is supplied, it specifies whether the affected lines are marked ashaving been changed (changed=1) or unchanged (changed=0).
Pretend the whole window has been changed, for purposes of drawingoptimizations.
Display a vertical line starting at(y,x) with lengthn consisting of thecharacterch.
Thecurses module defines the following data members:
A string representing the current version of the module. Also available as__version__.
Several constants are available to specify character cell attributes:
| Attribute | Meaning |
|---|---|
| A_ALTCHARSET | Alternate character set mode. |
| A_BLINK | Blink mode. |
| A_BOLD | Bold mode. |
| A_DIM | Dim mode. |
| A_NORMAL | Normal attribute. |
| A_REVERSE | Reverse background andforeground colors. |
| A_STANDOUT | Standout mode. |
| A_UNDERLINE | Underline mode. |
Keys are referred to by integer constants with names starting withKEY_.The exact keycaps available are system dependent.
| Key constant | Key |
|---|---|
| KEY_MIN | Minimum key value |
| KEY_BREAK | Break key (unreliable) |
| KEY_DOWN | Down-arrow |
| KEY_UP | Up-arrow |
| KEY_LEFT | Left-arrow |
| KEY_RIGHT | Right-arrow |
| KEY_HOME | Home key (upward+left arrow) |
| KEY_BACKSPACE | Backspace (unreliable) |
| KEY_F0 | Function keys. Up to 64 function keys aresupported. |
| KEY_Fn | Value of function keyn |
| KEY_DL | Delete line |
| KEY_IL | Insert line |
| KEY_DC | Delete character |
| KEY_IC | Insert char or enter insert mode |
| KEY_EIC | Exit insert char mode |
| KEY_CLEAR | Clear screen |
| KEY_EOS | Clear to end of screen |
| KEY_EOL | Clear to end of line |
| KEY_SF | Scroll 1 line forward |
| KEY_SR | Scroll 1 line backward (reverse) |
| KEY_NPAGE | Next page |
| KEY_PPAGE | Previous page |
| KEY_STAB | Set tab |
| KEY_CTAB | Clear tab |
| KEY_CATAB | Clear all tabs |
| KEY_ENTER | Enter or send (unreliable) |
| KEY_SRESET | Soft (partial) reset (unreliable) |
| KEY_RESET | Reset or hard reset (unreliable) |
| KEY_PRINT | |
| KEY_LL | Home down or bottom (lower left) |
| KEY_A1 | Upper left of keypad |
| KEY_A3 | Upper right of keypad |
| KEY_B2 | Center of keypad |
| KEY_C1 | Lower left of keypad |
| KEY_C3 | Lower right of keypad |
| KEY_BTAB | Back tab |
| KEY_BEG | Beg (beginning) |
| KEY_CANCEL | Cancel |
| KEY_CLOSE | Close |
| KEY_COMMAND | Cmd (command) |
| KEY_COPY | Copy |
| KEY_CREATE | Create |
| KEY_END | End |
| KEY_EXIT | Exit |
| KEY_FIND | Find |
| KEY_HELP | Help |
| KEY_MARK | Mark |
| KEY_MESSAGE | Message |
| KEY_MOVE | Move |
| KEY_NEXT | Next |
| KEY_OPEN | Open |
| KEY_OPTIONS | Options |
| KEY_PREVIOUS | Prev (previous) |
| KEY_REDO | Redo |
| KEY_REFERENCE | Ref (reference) |
| KEY_REFRESH | Refresh |
| KEY_REPLACE | Replace |
| KEY_RESTART | Restart |
| KEY_RESUME | Resume |
| KEY_SAVE | Save |
| KEY_SBEG | Shifted Beg (beginning) |
| KEY_SCANCEL | Shifted Cancel |
| KEY_SCOMMAND | Shifted Command |
| KEY_SCOPY | Shifted Copy |
| KEY_SCREATE | Shifted Create |
| KEY_SDC | Shifted Delete char |
| KEY_SDL | Shifted Delete line |
| KEY_SELECT | Select |
| KEY_SEND | Shifted End |
| KEY_SEOL | Shifted Clear line |
| KEY_SEXIT | Shifted Dxit |
| KEY_SFIND | Shifted Find |
| KEY_SHELP | Shifted Help |
| KEY_SHOME | Shifted Home |
| KEY_SIC | Shifted Input |
| KEY_SLEFT | Shifted Left arrow |
| KEY_SMESSAGE | Shifted Message |
| KEY_SMOVE | Shifted Move |
| KEY_SNEXT | Shifted Next |
| KEY_SOPTIONS | Shifted Options |
| KEY_SPREVIOUS | Shifted Prev |
| KEY_SPRINT | Shifted Print |
| KEY_SREDO | Shifted Redo |
| KEY_SREPLACE | Shifted Replace |
| KEY_SRIGHT | Shifted Right arrow |
| KEY_SRSUME | Shifted Resume |
| KEY_SSAVE | Shifted Save |
| KEY_SSUSPEND | Shifted Suspend |
| KEY_SUNDO | Shifted Undo |
| KEY_SUSPEND | Suspend |
| KEY_UNDO | Undo |
| KEY_MOUSE | Mouse event has occurred |
| KEY_RESIZE | Terminal resize event |
| KEY_MAX | Maximum key value |
On VT100s and their software emulations, such as X terminal emulators, there arenormally at least four function keys (KEY_F1,KEY_F2,KEY_F3,KEY_F4) available, and the arrow keys mapped toKEY_UP,KEY_DOWN,KEY_LEFT andKEY_RIGHT inthe obvious way. If your machine has a PC keyboard, it is safe to expect arrowkeys and twelve function keys (older PC keyboards may have only ten functionkeys); also, the following keypad mappings are standard:
| Keycap | Constant |
|---|---|
| Insert | KEY_IC |
| Delete | KEY_DC |
| Home | KEY_HOME |
| End | KEY_END |
| PageUp | KEY_NPAGE |
| PageDown | KEY_PPAGE |
The following table lists characters from the alternate character set. These areinherited from the VT100 terminal, and will generally be available on softwareemulations such as X terminals. When there is no graphic available, cursesfalls back on a crude printable ASCII approximation.
Note
These are available only afterinitscr() has been called.
| ACS code | Meaning |
|---|---|
| ACS_BBSS | alternate name for upper right corner |
| ACS_BLOCK | solid square block |
| ACS_BOARD | board of squares |
| ACS_BSBS | alternate name for horizontal line |
| ACS_BSSB | alternate name for upper left corner |
| ACS_BSSS | alternate name for top tee |
| ACS_BTEE | bottom tee |
| ACS_BULLET | bullet |
| ACS_CKBOARD | checker board (stipple) |
| ACS_DARROW | arrow pointing down |
| ACS_DEGREE | degree symbol |
| ACS_DIAMOND | diamond |
| ACS_GEQUAL | greater-than-or-equal-to |
| ACS_HLINE | horizontal line |
| ACS_LANTERN | lantern symbol |
| ACS_LARROW | left arrow |
| ACS_LEQUAL | less-than-or-equal-to |
| ACS_LLCORNER | lower left-hand corner |
| ACS_LRCORNER | lower right-hand corner |
| ACS_LTEE | left tee |
| ACS_NEQUAL | not-equal sign |
| ACS_PI | letter pi |
| ACS_PLMINUS | plus-or-minus sign |
| ACS_PLUS | big plus sign |
| ACS_RARROW | right arrow |
| ACS_RTEE | right tee |
| ACS_S1 | scan line 1 |
| ACS_S3 | scan line 3 |
| ACS_S7 | scan line 7 |
| ACS_S9 | scan line 9 |
| ACS_SBBS | alternate name for lower right corner |
| ACS_SBSB | alternate name for vertical line |
| ACS_SBSS | alternate name for right tee |
| ACS_SSBB | alternate name for lower left corner |
| ACS_SSBS | alternate name for bottom tee |
| ACS_SSSB | alternate name for left tee |
| ACS_SSSS | alternate name for crossover or big plus |
| ACS_STERLING | pound sterling |
| ACS_TTEE | top tee |
| ACS_UARROW | up arrow |
| ACS_ULCORNER | upper left corner |
| ACS_URCORNER | upper right corner |
| ACS_VLINE | vertical line |
The following table lists the predefined colors:
| Constant | Color |
|---|---|
| COLOR_BLACK | Black |
| COLOR_BLUE | Blue |
| COLOR_CYAN | Cyan (light greenish blue) |
| COLOR_GREEN | Green |
| COLOR_MAGENTA | Magenta (purplish red) |
| COLOR_RED | Red |
| COLOR_WHITE | White |
| COLOR_YELLOW | Yellow |
Thecurses.textpad module provides aTextbox class that handleselementary text editing in a curses window, supporting a set of keybindingsresembling those of Emacs (thus, also of Netscape Navigator, BBedit 6.x,FrameMaker, and many other programs). The module also provides arectangle-drawing function useful for framing text boxes or for other purposes.
The modulecurses.textpad defines the following function:
Draw a rectangle. The first argument must be a window object; the remainingarguments are coordinates relative to that window. The second and thirdarguments are the y and x coordinates of the upper left hand corner of therectangle to be drawn; the fourth and fifth arguments are the y and xcoordinates of the lower right hand corner. The rectangle will be drawn usingVT100/IBM PC forms characters on terminals that make this possible (includingxterm and most other software terminal emulators). Otherwise it will be drawnwith ASCII dashes, vertical bars, and plus signs.
You can instantiate aTextbox object as follows:
Return a textbox widget object. Thewin argument should be a cursesWindowObject in which the textbox is to be contained. The edit cursorof the textbox is initially located at the upper left hand corner of thecontaining window, with coordinates(0,0). The instance’sstripspaces flag is initially on.
Textbox objects have the following methods:
This is the entry point you will normally use. It accepts editingkeystrokes until one of the termination keystrokes is entered. Ifvalidator is supplied, it must be a function. It will be called foreach keystroke entered with the keystroke as a parameter; command dispatchis done on the result. This method returns the window contents as astring; whether blanks in the window are included is affected by thestripspaces attribute.
Process a single command keystroke. Here are the supported specialkeystrokes:
| Keystroke | Action |
|---|---|
| Control-A | Go to left edge of window. |
| Control-B | Cursor left, wrapping to previous line ifappropriate. |
| Control-D | Delete character under cursor. |
| Control-E | Go to right edge (stripspaces off) or endof line (stripspaces on). |
| Control-F | Cursor right, wrapping to next line whenappropriate. |
| Control-G | Terminate, returning the window contents. |
| Control-H | Delete character backward. |
| Control-J | Terminate if the window is 1 line,otherwise insert newline. |
| Control-K | If line is blank, delete it, otherwiseclear 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 movementis not possible. The following synonyms are supported where possible:
| Constant | Keystroke |
|---|---|
| KEY_LEFT | Control-B |
| KEY_RIGHT | Control-F |
| KEY_UP | Control-P |
| KEY_DOWN | Control-N |
| KEY_BACKSPACE | Control-h |
All other keystrokes are treated as a command to insert the givencharacter and move right (with line wrapping).
Return the window contents as a string; whether blanks in thewindow are included is affected by thestripspaces member.
This attribute is a flag which controls the interpretation of blanks inthe window. When it is on, trailing blanks on each line are ignored; anycursor motion that would land the cursor on a trailing blank goes to theend of that line instead, and trailing blanks are stripped when the windowcontents are gathered.
16.10.getpass — Portable password input
16.13.curses.ascii — Utilities for ASCII characters
Enter search terms or a module, class or function name.
