title: Get an uploaded file from a WTForms field
body: <p>In the Flask docs, the file upload example uses <code>&lt;input type="file" name="file"&gt;</code> then <code>request.files['file']</code> to get the file. I'm using a WTForms FileField.  How do I get the uploaded file when using WTForms rather than writing the input html myself?</p>