code: def read_csv_as_integer(csv_name, integer_columns, usecols=None):
      
      csv_path = os.path.join(DATA_FOLDER, csv_name)
      csv = pd.read_csv(csv_path, low_memory=False, usecols=usecols)
      for column in integer_columns:
          csv = csv[pd.to_numeric(csv[column], errors="coerce").notnull()]
      csv[integer_columns] = csv[integer_columns].apply(pd.to_numeric)
      return csv
docs: Returns a DataFrame from a .csv file stored in /data/raw/.
      Converts columns specified by 'integer_columns' to integer.