OSError: cannot open resource while trying to use ImageFont.py
<p>I am using python to generate token as security measure. Here is the code:</p>

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

        image=Image.new("RGBA",(220,20),(255,255,255))
        image_base=ImageDraw.Draw(image)
        font = ImageFont.truetype("arial.ttf", 15)
        font.size = 16
        image_base.text((80,0),emailed_password,(0,0,0),font=font)
        image_bytes=BytesIO()
        image.save(image_bytes,format='png')
        logo_file = open('static\images\RCI_logo.jpg', 'rb')
        logo_bytes = logo_file.read()
        logo_file.close()
        token_name='registration_token'
        secret_code_attachment = MIMEImage(image_bytes.getvalue(), name = '{0}.png'.format(token_name))
        secret_code_attachment.add_header('Content-ID', '&lt;{0}&gt;'.format(token_name))
        secret_code_attachment.add_header('Content-Disposition', 'inline')
        message.attach(secret_code_attachment)
        logo_file_name='logo_file_svg'
        logo_attachment = MIMEImage(logo_bytes, name = '{0}.jpg'.format(logo_file_name))
        logo_attachment.add_header('Content-ID', '&lt;{0}&gt;'.format(logo_file_name))
        logo_attachment.add_header('Content-Disposition', 'inline')
        message.attach(logo_attachment)
        html = 'some message'
        html_attachment = MIMEText(html, 'html')
        message.attach(html_attachment)
        smtpObj.sendmail(sender,receiver,message.as_string())
</code></pre>

<p>The error seems to be in ability to load font. Although I am importing ImageFont from PIL.</p>

<p>The error message is below:</p>

<pre><code>ERROR in app: Exception on /registration [POST], referer: http://my.com/registration

Traceback (most recent call last):, referer: http://my.com/registration

File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 1982, in wsgi_app, referer: http://my.com.com/registration

response = self.full_dispatch_request(), referer:    http://my.com/registration

File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 1614, in full_dispatch_request, referer: http://my.com/registration

rv = self.handle_user_exception(e), referer: http://my.com/registration

File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 1517, in handle_user_exception, referer: http://my.com/registration

reraise(exc_type, exc_value, tb), referer: http://my.com/registration

File "/usr/local/lib/python3.5/dist-packages/flask/_compat.py", line 33, in reraise, referer: http://my.com/registration

raise value, referer: http://my.com/registration

File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 1612, in full_dispatch_request, referer: http://my.com/registration

rv = self.dispatch_request(), referer: http://my.com/registration

File "/usr/local/lib/python3.5/dist-packages/flask/app.py", line 1598, in dispatch_request, referer: http://my.com/registration

return self.view_functions[rule.endpoint](**req.view_args), referer: http://my.com/registration

File "/var/www/rci/rciApp/__init__.py", line 260, in registration, referer: http://my.com/registration

font = ImageFont.truetype("arial.ttf", 15), referer: http://my/registration

File "/usr/lib/python3/dist-packages/PIL/ImageFont.py", line 239, in truetype, referer: http://my.com/registration

return FreeTypeFont(font, size, index, encoding), referer: http://my.com/registration

File "/usr/lib/python3/dist-packages/PIL/ImageFont.py", line 128, in __init__, referer: http://my.com/registration

self.font = core.getfont(font, size, index, encoding), referer: http://my.com/registration

OSError: cannot open resource, referer: http://my.com/registration
</code></pre>

<p>My understanding is that ImageFont is causing the problem because it cannot load proper font. I am not sure how to fix it. Even more puzzling is that it used to work until I put it on the server. </p>