title: Find element's index in pandas Series
body: <p>I know this is a very basic question but for some reason I can't find an answer. How can I get the index of certain element of a Series in python pandas? (first occurrence would suffice)</p>
  
  <p>I.e., I'd like something like:</p>
  
  <pre><code>import pandas as pd
  myseries = pd.Series([1,4,0,7,5], index=[0,1,2,3,4])
  print myseries.find(7) # should output 3
  </code></pre>
  
  <p>Certainly, it is possible to define such a method with a loop:</p>
  
  <pre><code>def find(s, el):
      for i in s.index:
          if s[i] == el: 
              return i
      return None
  
  print find(myseries, 7)
  </code></pre>
  
  <p>but I assume there should be a better way. Is there?</p>