code: def read_item_category(self):
      list_item_category = []
      dict_category = {}
      set_items = set()
      dict_item_category = {}
  
      with open(self.input_file, "r", encoding="utf-8") as infile:
          for line in infile:
              if line.strip():
                  inline = line.split(self.sep)
                  item, category = int(inline[0]), inline[1].rstrip()
  
                  list_item_category.append([item, category])
  
                  if category in dict_category:
                      dict_category[category] += 1
                  else:
                      dict_category[category] = 1
  
                  set_items.add(item)
  
                  if item not in dict_item_category:
                      dict_item_category[item] = []
                      dict_item_category[item].append(category)
                  else:
                      dict_item_category[item].append(category)
  
      return [
          dict_category,
          list_item_category,
          set_items,
          dict_item_category,
      ]
  
file_path: CaseRecommender/caserec/utils/process_data.py
imports: import pandas
  from caserec.utils.extra_functions import check_error_file
label_desc: Use image node_id 6 for calling the ReadFile obj's underlying member method code with example usage: obj.read_item_category() and returns: list