text: import numpy as np
  import pandas as pd
  print("Hi Github Users!")
  
  
  def obj_lister(df):
      """
      This function takes in a dataframe and returns a list of columns that
      contain objects
      """
      obj_list = []
      for col in df.select_dtypes([np.object]):
          obj_list.append(col)
      return obj_list
  
  
  # Adds a new class called "CleanDataFrame"
  class CleanDataFrame:
      def __init__(self, df):
          self.df = df
  
      def NaN_cleaning(self):
          """
          This function takes in a dataframe and cleans nulls by replacing with
          text. It returns a cleaned dataframe.
          """
          df = self.df.replace(np.nan, 'unknown')
          return df.reset_index(drop=True)
  
  
  print('Installed!')