title: Python: SyntaxError: keyword can't be an expression
body: <p>In a Python script I call a function from <code>rpy2</code>, but I get this error:</p>
  
  <pre><code>#using an R module 
  res = DirichletReg.ddirichlet(np.asarray(my_values),alphas,
                                log=False, sum.up=False) 
  SyntaxError: keyword can't be an expression
  </code></pre>
  
  <p>What exactly went wrong here?</p>