input: Write a function to modify the given Python code to handle errors. The function should open a file, read its content, and parse it as JSON. If the file does not exist, it should print "The file specified does not exist." If the file content is not in a valid JSON format, it should print "The file specified is not in a valid JSON format."
  
  def read_data_from_json(filename):
      try:
          with open(filename, 'r') as f:
              data = json.load(f)
          return data
      except FileNotFoundError:
          print("The file specified does not exist.")
      except json.decoder.JSONDecodeError:
          print("The file specified is not in a valid JSON format.")
  
  assert read_data_from_json('nonexistent_file.json')=="The file specified does not exist."
  assert read_data_from_json('invalid_json_file.json')=="The file specified is not in a valid JSON format."
  assert read_data_from_json('valid_file.json')=={"key": "value"}
output: def read_data_from_json(filename):
      try:
          with open(filename, 'r') as f:
              data = json.load(f)
          return data
      except FileNotFoundError:
          print("The file specified does not exist.")
      except json.decoder.JSONDecodeError:
          print("The file specified is not in a valid JSON format.")