A Python script which prints a brainfuck program in the shape of an xmas tree, which prints an xmas tree. `python3 tree.py [size of tree e.g 11 ]`

tree.py

import sys
import io

SPACE = 32
CHAR_X = 88
NEWLINE = 10

def print_tree(s):
    lines = []

    width = 1

    while len(s) >= width:
        line, s = s[:width], s[width:]
        lines.append(line)
        width += 2
    if s:
        lines.append(s)
    else:
        lines.append('#')

    output = io.StringIO()
    for line in lines:
        print(('{:^' + str(width) + 's}').format(line), file=output)
    return output.getvalue()


def bf_tree(levels=5):
    program = []
    program.append(SPACE * "+")
    program.append(">")
    program.append(CHAR_X * "+")
    program.append(">")
    program.append(NEWLINE * "+")

    max_no_spaces = levels
    for level in range(1, levels + 1):
        program.append("<<")  # move cursor to SPACE cell
        program.append((max_no_spaces-level) * ".")  # output spaces
        program.append(">")  # move cursor to CHAR_X cell
        if level == 1:
            program.append(".")
        else:
            program.append((level*2-1) * ".")
        program.append(">")  # move cursor to NEWLINE cell
        program.append(".")
    program.append("<<")  # move cursor to SPACE
    program.append((max_no_spaces-1) * ".")
    program.append(">")  # move cursor to CHAR_X
    program.append("---")  # deduct 3 from X to make U
    program.append(".")
    return ''.join(program)


if __name__ == '__main__':
    try:
        levels = int(sys.argv[1])
    except:
        levels = 5
    print(print_tree(bf_tree(levels)))