title: How to replace comma-separated text in a column?
body: <p>One of the columns in my dataframe contains a comma-separated text, like "One, two, three":</p>
  
  <pre><code>df =
    Col1               Col2
    One, two, three    Abc
    Two                Def
  </code></pre>
  
  <p>I want to replace <code>One, two, three</code> by <code>One_two_three</code>.</p>
  
  <p>If I apply this code:</p>
  
  <pre><code>df['Col1'].replace("One, two, three", "One_two_three",inplace=True)
  </code></pre>
  
  <p>... it does not change anything. Why?</p>