title: SyntaxError: invalid character in identifier - Pytorch 1.3.1
body: <p>When executing the following method:</p>
  
  <pre><code>def flatten(t):
      t = t.reshape(1, −1)
      t = t.squeeze()
      return t
  </code></pre>
  
  <p>Python complains about the second argument.</p>
  
  <pre><code>  File "pytorch.py", line 16
  t = t.reshape(1, −1)
                    ^       SyntaxError: invalid character in identifier
  </code></pre>
  
  <p>My pytorch version is 1.3.1.
  I already tried to remove the space before the argument with no effect. Any ideas?</p>