title: Replace partial string/char in columdata of Panda dataframe
body: <p>I have a dataframe as follows:</p>
  
  <pre><code>    Name   Rating
  0   ABC    Good 
  1   XYZ    Good @
  2   GEH    Good 
  3   ABH    *
  4   FEW    Normal
  </code></pre>
  
  <p>Here I want to replace in the <code>Rating</code> element if it contain <code>@</code> it should replace by <code>Can be improve</code> , if it contain <code>*</code> then <code>Very Poor</code>. I have tried with following but it replace whole string. But I want to replace only the <code>special char</code> if it present.But it solves for another case if only <code>special char</code> is present.</p>
  
  <pre><code>import pandas as pd
  df = pd.DataFrame() # Load with data
  df['Rating'] = df['Rating'].str.replace('.*@+.*', 'Can be improve')
  </code></pre>
  
  <p>is returning </p>
  
  <pre><code>    Name   Rating
  0   ABC    Good 
  1   XYZ    Can be improve
  2   GEH    Good 
  3   ABH    Very Poor
  4   FEW    Normal
  </code></pre>
  
  <p>Can anybody help me out with this?</p>