Here is the main function

WIDTH = 221
HEIGHT = 100;
def create_pileup_images(candidate_variants):
 for candidate in candidate_variants:
 for biallelic_variant in split_into_biallelics(candidate):
 start = biallelic_variant.start - (WIDTH-1) / 2
 end = WIDTH - span_start
 ref_bases = reference.get_bases(start, end)
 image = Image(WIDTH, HEIGHT)
 row_i = fill_reference_pixels(ref, image)
 for read in reads.get_overlapping(start, end):
 if row_i < HEIGHT and is_usable_read(read):
 add_read(image, read, row_i)
 row_i += 1
 yield image

def fill_reference_pixels(ref, image):
 for row in range(5):
 for col in range(WIDTH):
 alpha = 0.4
 ref_base = ref[col]
 red = get_base_color(ref_base)
 green = get_quality_color(60) # The reference is high quality
 blue = get_strand_color(True) # The reference is on the positive strand
 image[row, col] = make_pixel(red, green, blue, alpha)
 return 5

Here is the main function:

WIDTH = 221
HEIGHT = 100

def create_pileup_images(candidate_variants):
    for candidate in candidate_variants:
        for biallelic_variant in split_into_biallelics(candidate):
            start = biallelic_variant.start - (WIDTH - 1) / 2
            end = WIDTH - span_start
            ref_bases = reference.get_bases(start, end)
            image = Image(WIDTH, HEIGHT)
            row_i = fill_reference_pixels(ref_bases, image)
            for read in reads.get_overlapping(start, end):
                if row_i < HEIGHT and is_usable_read(read):
                    add_read(image, read, row_i)
                    row_i += 1
            yield image

def fill_reference_pixels(ref, image):
    for row in range(5):
        for col in range(WIDTH):
            alpha = 0.4
            ref_base = ref[col]
            red = get_base_color(ref_base)
            green = get_quality_color(60)  # The reference is high quality
            blue = get_strand_color(True)  # The reference is on the positive strand
            image[row, col] = make_pixel(red, green, blue, alpha)
    return 5