title: Exact match of string in pandas python
body: <p>I have a column in data frame which ex df: </p>
  
  <pre><code>  A
  0 Good to 1. Good communication EI : tathagata.kar@ae.com
  1 SAP ECC Project System  EI: ram.vaddadi@ae.com
  2 EI : ravikumar.swarna  Role:SSE  Minimum Skill  
  </code></pre>
  
  <p>I have a list of of strings </p>
  
  <pre><code>ls=['tathagata.kar@ae.com','a.kar@ae.com']
  </code></pre>
  
  <p>Now if i want to filter out</p>
  
  <pre><code>for i in range(len(ls)):
     df1=df[df['A'].str.contains(ls[i])
          if len(df1.columns!=0):
              print ls[i]
  </code></pre>
  
  <p>I get the output</p>
  
  <pre><code>tathagata.kar@ae.com 
  a.kar@ae.com
  </code></pre>
  
  <p>But I need only <code>tathagata.kar@ae.com</code></p>
  
  <p>How Can It be achieved?
  As you can see I've tried <strong>str.contains</strong> But I need something for extact match</p>