title: Delete the comma from a string in csv
body: <p>I am merging two csv files and trying to delete a comma from the Entity column, which exists in both csvs. Even though the script works fine and does not blow up the comma still shows up in both the individual csvs and the merged one. How can I delete the comma from the column? </p>
  
  <pre><code>import pandas as pd
  
  first = pd.read_csv('C:/Users/first csv.csv')
  first['project_id'] = 1
  first['Entity'] = first['Entity'].map(lambda x: x.lstrip(','))
  
  second = pd.read_csv('C:/Users/second csv.csv')
  second['project_id'] = 2
  second['Entity'] = second['Entity'].map(lambda x: x.lstrip(','))
  
  merged = pd.concat([first, second], ignore_index = True)
  merged.to_csv('C:/both files.csv', index=False)
  
  Print "Let's get to work"
  </code></pre>