title: python assert with and without parenthesis
body: <p>Here are four simple invocations of assert:</p>
  
  <pre><code>&gt;&gt;&gt; assert 1==2
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in ?
  AssertionError
  
  &gt;&gt;&gt; assert 1==2, "hi"
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in ?
  AssertionError: hi
  
  &gt;&gt;&gt; assert(1==2)
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in ?
  AssertionError
  
  &gt;&gt;&gt; assert(1==2, "hi")
  </code></pre>
  
  <p>Note that the last one does not raise an error.  What is the difference between calling assert with or without parenthesis that causes this behavior?  My practice is to use parenthesis, but the above suggests that I should not.</p>