title: add a string suffx to each value in a string column using Pandas if it doesn't contain a value
body: <p>I want to add "raw" to the end of each value in a string column if it doesn't contain the word raw. </p>
  
  <pre><code>from pandas import pandas as pd
  df = pd.read_csv("files/Template_DataCatalogue_Test.csv", sep=";")
  df.drop(df.index[3:], inplace=True)
  df = df[~df["Title"].str.contains("raw"), "raw " + df["Title"].astype(str)]
  print(df)
  </code></pre>