epub converter: add color conversion, update adding style tags

src/util/color_reader.py

@@ -0,0 +1,87 @@
+from webcolors import html4_hex_to_names, hex_to_rgb, rgb_to_name
+
+
+def closest_colour_rgb(requested_colour):
+    min_colours = {}
+    for key, name in html4_hex_to_names.items():
+        r_c, g_c, b_c = hex_to_rgb(key)
+        rd = (r_c - requested_colour[0]) ** 2
+        gd = (g_c - requested_colour[1]) ** 2
+        bd = (b_c - requested_colour[2]) ** 2
+        min_colours[(rd + gd + bd)] = name
+
+    return min_colours[min(min_colours.keys())]
+
+
+def get_rgb_colour_name(c):
+    try:
+        closest_name = actual_name = rgb_to_name(c, 'html4')
+    except ValueError:
+        closest_name = closest_colour_rgb(c)
+        actual_name = None
+    if actual_name:
+        return actual_name
+    else:
+        return closest_name
+
+
+def get_hex_colour_name(c):
+    try:
+        c = hex_to_rgb(c)
+    except ValueError:
+        return ''
+
+    try:
+        closest_name = actual_name = rgb_to_name(c, 'html4')
+    except ValueError:
+        closest_name = closest_colour_rgb(c)
+        actual_name = None
+    if actual_name:
+        return actual_name
+    else:
+        return closest_name
+
+
+def str2color_name(s: str):
+    if 'rgb' in s:
+        s = s.replace('rgb', '').replace('(', '').replace(')', '')
+        try:
+            rgb = [int(x) for x in s.split(',')]
+            rgb = tuple(rgb)
+        except ValueError:
+            return ''
+        if len(rgb) != 3:
+            return ''
+        name = get_rgb_colour_name(rgb)
+        return  name
+
+    elif '#' in s:
+        name = get_hex_colour_name(s)
+        return name
+
+    else:
+        return ''
+
+
+if __name__ == '__main__':
+
+    str2color_name('rgb(139, 0, 0)')
+
+    colors = [
+        (75, 0, 130), (255, 0, 255),
+        (139, 69, 19), (46, 139, 87),
+        (221, 160, 221)
+    ]
+
+    hex_colors = [
+        '#96F', '#000', '#4C4C4C', '#A00', '#99F'
+    ]
+
+    for c in colors:
+        name = get_rgb_colour_name(c)
+        print("Actual colour:", c, ", closest colour name:", name)
+
+    for c in hex_colors:
+        name = get_hex_colour_name(c)
+        print("Actual colour:", c, ", closest colour name:", name)
+        print()