title: Creating a Cumulative Frequency Column in a Dataframe Python
body: <p>I am trying to create a new column named 'Cumulative Frequency' in a data frame where it consists of all the previous frequencies to the frequency for the current row as shown here.</p>
  
  <p><a href="https://i.stack.imgur.com/jQ39A.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jQ39A.jpg" alt="enter image description here"></a></p>
  
  <p>What is the way to do this?</p>