code: def load(self):
          
  
          df = pd.read_csv(self.input_file,
                           encoding='utf8')
  
          df['wiki_id'] = df['artist'].str.split('/').str[-1]
  
          # some years of birth are given as timestamps with prefix 't', convert to string
          timestamps = df['dob'].str.startswith('t')
          df.loc[timestamps, 'dob'] = df.loc[timestamps, 'dob'].str[1:].apply(
              lambda s: str(datetime.datetime.fromtimestamp(float(s))))
  
          df['year_of_birth'] = df['dob'].str[:4].astype(int)
  
          return df
docs: Load the data file, do some basic type conversions