How do I deal with lines that are longer than the Curses window in Python?

Question

I'd like my curses application to display the absolute path of the current file that it is working with as it iterates. These can get longer than the window, running into the next line. If the next file path is shorter, difference in length is not overwritten, leading to mangled strings. What is the best practice way of fixing this problem?

Edit: Python 3 sample code on Mac OS X

from os import walk
import curses
from os import path

stdscr = curses.initscr()
curses.noecho()
for root, dirs, files in walk("/Users"):
    for file in files:
        file_path = path.join(root, file)
        stdscr.addstr(0, 0, "Scanning: {0}".format(file_path))
        stdscr.clearok(1)
        stdscr.refresh()

Answer 1

Assuming you don't want to use a window, the simplest solution is:

1. Use addnstr instead of addstr to never write more characters than fit on the line, and
2. Use clrtoeol to erase any leftover characters after the new path.

For example:

from scandir import walk
import curses
from os import path

try:
    stdscr = curses.initscr()
    curses.noecho()
    _, width = stdscr.getmaxyx()
    for root, dirs, files in walk("/Users"):
        for file in files:
            file_path = path.join(root, file)
            stdscr.addnstr(0, 0, "Scanning: {0}".format(file_path), width-1)
            stdscr.clrtoeol()
            stdscr.clearok(1)
            stdscr.refresh()
finally:
    curses.endwin()

---

If you want to do this by creating a larger-than-fullscreen window and clipping it to the terminal, read up on newpad . For a trivial case line this, it won't be any simpler, but for more complex cases it might be what you're looking for:

from scandir import walk
import curses
from os import path

try:
    stdscr = curses.initscr()
    curses.noecho()
    height, width = stdscr.getmaxyx()
    win = curses.newpad(height, 16383)
    for root, dirs, files in walk("/Users"):
        for file in files:
            file_path = path.join(root, file)
            win.addstr(0, 0, "Scanning: {0}".format(file_path))
            win.clrtoeol()
            win.clearok(1)
            win.refresh(0, 0, 0, 0, height-1, width-1)
finally:
    curses.endwin()