title: Regex to check validation in Django
body: <p>I am trying to code for the following validation in Django:
  "Capital Letters are allowed only as of the first-word letter or only if all letters in a word are uppercase"
  I have done this till now, but it is failing, Can someone please help me?</p>
  
  <p>For example:</p>
  
  <pre><code>This is The GOOD day - acceptable
  ThIS is THE gOOD day - not acceptable
  </code></pre>
  
  <p>My code:</p>
  
  <pre><code>RegexValidator(
          regex='(^[A-Z][\sa-z0-9]+$)|(^([A-Z]\w*\s*)+$)',
          message='Capital Letters are allowed only as first word letter or only if all letters in word are uppercase',
          code='invalid_capitalisation'
  )
  </code></pre>