title: Python3: TypeError: 'float' object is not subscriptable
body: <p>master_frame["primary_sector"]=master_frame["category_list"].str.split("|").apply(lambda x: x[0])</p>
  
  <p>I have a column- "category_list" which is a combination of names delimited by "|". I have to take the first name from that column and create a new column- "primary_sector".</p>
  
  <p>I am running the above code but it is giving me this error: "float" object not subscriptable.
  I don't understand, why it is showing an error. Am I being clear enough?</p>