text: import pandas as pd
  
  
  def check_region_info(df: 'pd.DataFrame') -> 'pd.DataFrame':
      """Check if region column exists.
  
      If not exists, it creates the column from the SiteName information
  
      :param df: the input dataframe
      :type df: pandas.DataFrame
      :return: the data frame with the new column
      :rtype: pandas.DataFrame
      """
      if 'Region' not in df.columns:
          # Example lambda map:
          #  T2_US_Vanderbilt -> us
          df['Region'] = df['SiteName'].map(
              lambda elm: elm.split("_")[1].lower()
          )
      return df
  
  
  def check_filename_info(df: 'pd.DataFrame') -> 'pd.DataFrame':
      """Check if filename stats exist.
  
      If not exist, it creates the columns from the filename information
  
      :param df: the input dataframe
      :type df: pandas.DataFrame
      :return: the data frame with the new column
      :rtype: pandas.DataFrame
      """
      if 'Campain' not in df.columns:
          # Example lambda map:
          #  /store/data/Run2016B/DoubleEG/MINIAOD/03Feb2017_ver2-v2/50000/0EEFA768-E2EA-E611-86FE-0025905A610A.root -> Run2016B
          df['Campain'] = df['Filename'].map(
              lambda elm: elm.split("/")[3]
          )
      if 'Process' not in df.columns:
          # Example lambda map:
          #  /store/data/Run2016B/DoubleEG/MINIAOD/03Feb2017_ver2-v2/50000/0EEFA768-E2EA-E611-86FE-0025905A610A.root -> DoubleEG
          df['Process'] = df['Filename'].map(
              lambda elm: elm.split("/")[4]
          )
      return df
  
  
  def get_object_columns(df: 'pd.DataFrame') -> list:
      """Returns the name of the columns that are objects (string)
  
      :param df: the input dataframe
      :type df: pandas.DataFrame
      :return: the list of the column names that are string
      :rtype: list
      """
      return [
          df.columns[idx]
          for idx, type_ in enumerate(df.dtypes)
          if type_ == pd.StringDtype
      ]
  
  
  def get_unique_values(df: 'pd.Series') -> list:
      """Returns unique values from a pandas series.
  
      :param df: The value series
      :type df: pandas.Series
      :return: the unique values
      :rtype: list
      """
      return df.unique().tolist()
  