title: convert python2.6 cantera1.8 to python2.7 cantera2.2
body: <p>I am new on chemical network model. Currently I am converting a previous student python code to adapt the new version in the lab as titled.</p>
  
  <p>firstly, a gas mixture from mechanism (pre defined) is defined</p>
  
  <pre><code>gas_mix = ct.import_phases(mech,['gas'])
  </code></pre>
  
  <p>then, I want to get the number of the species and use cantera nSpecies</p>
  
  <pre><code>nsp = gas_mix.nSpecies()
  </code></pre>
  
  <p>and I got the error message as</p>
  
  <blockquote>
    <p>AttributeError: 'list' object has no attribute 'nSpecies'</p>
  </blockquote>
  
  <p>Also I tried:</p>
  
  <pre><code>nsp = gas_mix.n_species
  </code></pre>
  
  <p>and it also shows </p>
  
  <blockquote>
    <p>AttributeError: 'list' object has no attribute</p>
  </blockquote>
  
  <p>Would you please kindly help me on this ?
  Thank you and best regards,
  YouBe</p>