advent/toolkit.py

def render(grid, brush):
    if isinstance(brush, str):
        brush = {i: c for i, c in enumerate(brush)}
    xmin, *_, xmax = sorted(int(p.real) for p in grid)
    ymin, *_, ymax = sorted(int(p.imag) for p in grid)
    brush[None] = ' '
    rendered = ''
    for y in range(ymin, ymax + 1):
        for x in range(xmin, xmax + 1):
            rendered += brush[grid.get(complex(x, y))]
        rendered += '\n'
    return rendered