ImageFont detect missing glyph (Python Pillow)
<p>Here is a short <a href="http://pillow.readthedocs.io/en/3.1.x/reference/ImageFont.html" rel="nofollow">example</a>.</p>

<pre><code>from PIL import ImageFont, ImageDraw

draw = ImageDraw.Draw(image)

# use a bitmap font
font = ImageFont.load("arial.pil")

draw.text((10, 10), "hello", font=font)

# use a truetype font
font = ImageFont.truetype("arial.ttf", 15)

draw.text((10, 25), "world", font=font)
</code></pre>

<blockquote>
  <p>I want to know if the font is missing any glyphs from the rendered text.</p>
</blockquote>

<p>When I try to render a glyph that is missing I get an empty square.</p>

<pre><code>draw.text((10, 10), chr(1234), font=font)
</code></pre>

<ul>
<li>How to programmatically determine missing glyphs?</li>
<li>How to list available glyphs in a <strong>ttf</strong> file?</li>
</ul>

<p>The two questions are almost the same.</p>

<blockquote>
  <p>I would prefer using Pillow to determine what I want.
  Other modules from PyPI are welcome as well.</p>
</blockquote>