问题
Using python curses I am trying to write some text in to window.
But when I reach end of window i get addstr() returned ERR
how to scroll the output page by page or line by line.? how can I bind SPACE key or down arrow ?
here is my code:
try:
screen = curses.initscr()
screen.immedok(True)
curses.start_color()
curses.init_pair(1, curses.COLOR_GREEN, curses.COLOR_BLACK)
curses.init_pair(2, curses.COLOR_WHITE, curses.COLOR_BLACK)
screen.bkgd(curses.color_pair(2))
screen.scrollok(1)
screen.border(0)
p = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
(output, err) = p.communicate()
linenumber = 1
for line in getline(output):
if linenumber <= 2:
# First two lines are header, mark bold
screen.addstr(linenumber, 2, line, curses.color_pair(1)|curses.A_BOLD)
else:
screen.addstr(linenumber, 2, line)
linenumber += 1
screen.getch()
curses.endwin()
except Exception, e:
print "\n\033[1;91m[FAILED]\033[0m Interrupt ", e
logging.error(e, exc_info=True)
curses.endwin()
回答1:
This is the answer to: How to make a scrolling menu in python-curses
This code allows you to create a little menu in a box from a list of strings.
You can also use this code getting the list of strings from a sqlite query or from a csv file.
To edit the max number of rows of the menu you just have to edit max_row.
If you press enter the program will print the selected string value and its position.
from __future__ import division #You don't need this in Python3
import curses
from math import *
screen = curses.initscr()
curses.noecho()
curses.cbreak()
curses.start_color()
screen.keypad( 1 )
curses.init_pair(1,curses.COLOR_BLACK, curses.COLOR_CYAN)
highlightText = curses.color_pair( 1 )
normalText = curses.A_NORMAL
screen.border( 0 )
curses.curs_set( 0 )
max_row = 10 #max number of rows
box = curses.newwin( max_row + 2, 64, 1, 1 )
box.box()
strings = [ "a", "b", "c", "d", "e", "f", "g", "h", "i", "l", "m", "n" ] #list of strings
row_num = len( strings )
pages = int( ceil( row_num / max_row ) )
position = 1
page = 1
for i in range( 1, max_row + 1 ):
if row_num == 0:
box.addstr( 1, 1, "There aren't strings", highlightText )
else:
if (i == position):
box.addstr( i, 2, str( i ) + " - " + strings[ i - 1 ], highlightText )
else:
box.addstr( i, 2, str( i ) + " - " + strings[ i - 1 ], normalText )
if i == row_num:
break
screen.refresh()
box.refresh()
x = screen.getch()
while x != 27:
if x == curses.KEY_DOWN:
if page == 1:
if position < i:
position = position + 1
else:
if pages > 1:
page = page + 1
position = 1 + ( max_row * ( page - 1 ) )
elif page == pages:
if position < row_num:
position = position + 1
else:
if position < max_row + ( max_row * ( page - 1 ) ):
position = position + 1
else:
page = page + 1
position = 1 + ( max_row * ( page - 1 ) )
if x == curses.KEY_UP:
if page == 1:
if position > 1:
position = position - 1
else:
if position > ( 1 + ( max_row * ( page - 1 ) ) ):
position = position - 1
else:
page = page - 1
position = max_row + ( max_row * ( page - 1 ) )
if x == curses.KEY_LEFT:
if page > 1:
page = page - 1
position = 1 + ( max_row * ( page - 1 ) )
if x == curses.KEY_RIGHT:
if page < pages:
page = page + 1
position = ( 1 + ( max_row * ( page - 1 ) ) )
if x == ord( "\n" ) and row_num != 0:
screen.erase()
screen.border( 0 )
screen.addstr( 14, 3, "YOU HAVE PRESSED '" + strings[ position - 1 ] + "' ON POSITION " + str( position ) )
box.erase()
screen.border( 0 )
box.border( 0 )
for i in range( 1 + ( max_row * ( page - 1 ) ), max_row + 1 + ( max_row * ( page - 1 ) ) ):
if row_num == 0:
box.addstr( 1, 1, "There aren't strings", highlightText )
else:
if ( i + ( max_row * ( page - 1 ) ) == position + ( max_row * ( page - 1 ) ) ):
box.addstr( i - ( max_row * ( page - 1 ) ), 2, str( i ) + " - " + strings[ i - 1 ], highlightText )
else:
box.addstr( i - ( max_row * ( page - 1 ) ), 2, str( i ) + " - " + strings[ i - 1 ], normalText )
if i == row_num:
break
screen.refresh()
box.refresh()
x = screen.getch()
curses.endwin()
exit()
回答2:
The problem is that your calls to screen.addstr have asked for a line number past the end of the screen. Taking into account the box which you have drawn on the screen, a better approach would be to create a new window just inside the box (using curses.newwin for example) and write the addstr calls within that window.
Your example does not compile as given. Here is a working example:
import curses
import logging
import subprocess
import sys
command = "ls -l /bin"
try:
screen = curses.initscr()
screen.immedok(True)
curses.start_color()
curses.init_pair(1, curses.COLOR_GREEN, curses.COLOR_BLACK)
curses.init_pair(2, curses.COLOR_WHITE, curses.COLOR_BLACK)
screen.bkgd(curses.color_pair(2))
screen.border(0)
boxed = curses.newwin(curses.LINES - 2, curses.COLS - 2, 1, 1)
boxed.scrollok(1)
p = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
(output, err) = p.communicate()
linenumber = 1
for line in output.split("\n"):
if linenumber <= 2:
# First two lines are header, mark bold
boxed.addstr(line, curses.color_pair(1)|curses.A_BOLD)
else:
boxed.addstr(line)
boxed.addch("\n")
linenumber += 1
boxed.getch()
screen.getch()
curses.endwin()
except Exception, e:
print "\n\033[1;91m[FAILED]\033[0m Interrupt ", e
logging.error(e, exc_info=True)
来源：https://stackoverflow.com/questions/30795161/scroll-page-by-page-or-line-by-line-using-python-curses