lines.py

def get_lengths(num_lines, line_length):
    "Get n lines, totaling a particular length."
    lengths = np.random.random(num_lines)
    lengths *= line_length / np.sum(lengths)
    return lengths

def lines(line_length, page_width):
    "Get a random number of lines, with n-1 gaps of varying length in between."
    num_lines = np.random.randint(1,10)
    lengths = get_lengths(num_lines, line_length)
    gaps = get_lengths(num_lines - 1, page_width - line_length)
    return lengths, gaps