def RenameColumns(df_old, renames):
    """
  Rename the column headers for a spark dataframe
  
  Parameters:
  -----------
  df_old : spark.DataFrame
      Initial Data Frame
  
  renames : list
      List of columns to rename, like:

  Returns:
  -------
  None
  
  Example:
  -----------
  df_new = ws.RenameColumns(df_old,renames)
  """
    df_new = df_old
    for rename in renames:
        df_new = df_new.withColumnRenamed(rename[0], rename[1])
    print('Column headers are renamed successfully...')
    return df_new
