Python curses box() is made of 6s and 0s

Question

So I ran into an interesting error/bug, I don't know which yet, but when running my Python curses script using the box() method I got the following result:

The desired and expected out put is to be a normal box... made of lines.

Here is the code for the script:


import curses
import init
import os
import time

MONSTER_LIST = init.init()
ENCOUNTER = []

def main(scr):

    curses.curs_set(0)

    scr.clear()
    h, w = scr.getmaxyx()

    get_number = "Number of players in party?"
    center_y, center_x = h//2, w//2 - len(get_number)//2
    scr.addstr(center_y, center_x, get_number)
    scr.refresh()
    NUMBER = int(scr.getstr())

    scr.clear()
    get_number = "Average rounded level of the Party"
    center_y, center_x = h//2, w//2 - len(get_number)//2
    scr.addstr(center_y, center_x, get_number)
    scr.refresh()
    LEVEL = int(scr.getstr())

    y = h-1

    bottom_text = "[S]earch [H]omebrew, S[A]ve, [Q]uit"

    FLAG = True

    scr.clear()

    encounter_y, encounter_x = h-2, w-2
    while FLAG:

        scr.addstr(0,0, 'D&D Encounter Builder')
        scr.addstr(y,0, bottom_text)
        Encounter_window = curses.newwin(encounter_y, encounter_x,1,1)
        encounter_box_y, encounter_box_x = Encounter_window.getmaxyx()
        Encounter_window.box(encounter_box_y, encounter_box_x)
        Encounter_window.addstr(1,2, 'Encounter list')
        Encounter_window.addstr(encounter_box_y-3, 2, f"Difficulty = {init.cr_calculation(NUMBER, LEVEL, ENCOUNTER)}")
        scr.refresh()
        Encounter_window.refresh()

        CHOICE = scr.getch()

        FLAG = False

curses.wrapper(main)

If this helps, I am using Arch 5.9.8-arch1-1 and I am using st-256 for my terminal emulator.

Thanks for the help in advance

score 1 · Accepted Answer · answered Nov 17 '20 at 01:35

This is a documented feature of curses which the Python binding uses:

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

Your example isn't setting the box size, but instead the characters used to draw it.

The character "0" has the value 48. Actually your horizontal characters aren't 0's, but probably

216    Ø

If you're seeing 6's for the vertical character, that is because the character for "6" happens to be 48 (0) + 6 = 54.

Thank you, I am glad it is that i was using the package wrong and that it was not finicky. — Adam Kalinowski, Nov 17 '20 at 12:54

score 0 · Answer 2 · answered Nov 16 '20 at 14:30

False alarm.

Turns out, this is a weird bug with curses that I haven't seen documented yet. If you give the box() method the dimensions of the window you are working with, it wigs out and doesnt know how to draw itself.

The simple solution is:

        Encounter_window.box(encounter_box_y, encounter_box_x)

to

        Encounter_window.box()

This seems really finicky and strange to me, so I would like some one to explain what is going on here.

Thanks anyways.

Python curses box() is made of 6s and 0s

2 Answers2