a probably buggy line-wrapping test script try to mininize the badness (like the algorithm by D.E.Knuth)

linewrap.py

#!/usr/bin/env python3
#-*-coding:utf-8-*-
from PIL import ImageFont

font_path = "/usr/share/fonts/truetype/freefont/FreeSerif.ttf"
font_size = 15
line_width = 360 # in px

font = ImageFont.truetype(font_path, font_size)


paragraph = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum a rhoncus nibh. Mauris quis elit ligula. Sed eget dolor nec arcu vulputate feugiat at a sapien. Donec aliquet dui ex, sit amet vestibulum dolor finibus sit amet. Vivamus pretium pretium dui. Donec feugiat ac nibh eget scelerisque. Pellentesque quis lacinia mi. Nam aliquam, mauris sed vehicula suscipit, arcu nulla fringilla diam, eget varius risus sapien in eros. Cras sem ante, dignissim pulvinar semper congue, luctus eget sapien."



# convert paragraph to word array
def para_split(para):
	return para.split(" ")

word_array = para_split(paragraph)
word_width_array = [font.getsize(word)[0] for word in word_array] #store the width of each word
space_width = font.getsize(" ")[0] # the width of the halt-width space char

# the cost of the line from word_array[begin] to word_array[end]
def cost(word_width_array, begin, end, line_width, space_width):
	word_width_sum = sum(word_width_array[begin:end+1])
	space_width_sum = (end-begin) * space_width

	cost = (line_width - word_width_sum - space_width_sum) ** 3

	if cost < 0:
		return float("infinity")
	else:
		return cost

linebreak = [] # store the (i+1)th word that a linebreak("\v\r") follows.


f_solve = [False for i in range(len(word_array))]
f_value = [float("infinity") for i in range(len(word_array))]
break_point_array = [0 for i in range(len(word_array))]

def f(x):
	if f_solve[x] == True:
		return f_value[x]
	else:
		raw = cost(word_width_array, 0, x, line_width, space_width)
		if raw < float("infinity"):
			f_solve[x] = True
			f_value[x] = raw
			return raw
		else:
			break_point = 0
			min_cost = float("infinity")

			for i in range(0,x):
				raw = f(i) + cost(word_width_array, i+1, x, line_width, space_width)
				if raw < min_cost:
					min_cost = raw
					break_point = i
			f_solve[x] = True
			f_value[x] = min_cost
			break_point_array[x] = break_point

			return min_cost


def break_point(x):
	real_break_point_array = []
	i = x
	while i != 0:
		real_break_point_array = [i] + real_break_point_array
		i = break_point_array[i]
	return real_break_point_array

def g(x):
	return [f(x-1), break_point(x-1)]
	

def linebreak(text_array):
	real_break_point_list = g(len(text_array))[1]
	print(real_break_point_list)
	
	for i in range(len(real_break_point_list)):
		text_array.insert(real_break_point_list[i]+i+1,'\v\r')

	return " ".join(text_array)



print(linebreak(word_array))