title: Cant iterate through multiple pandas series
body: <p>So I was attempting to iterate through two series that I obtained from a Pandas DF, and I found that I could not iterate through them to return numbers less than 280.000. I also realized that I could not iterate over lists either. Is there any way I can iterate over multiple lists, series, etc? thanks.
  Example below:</p>
  
  <pre><code>two_series = df['GNP'], df['Population']
  
  def numb():
              for i in two_series:
                  if i &lt; 280.000:
                      print(i)
  </code></pre>