new_contents: """Use a generator with numpy loadtxt"""
  
  import numpy as np
  
  
  def file_stream(file_name):
      for line in open(file_name):
          yield line
  
  
  def demo_use():
      file_name = 'census_abs2011_summary.csv'
      # Skip the header, return 3 columns: the age, weekly rental and total family income
      data = np.loadtxt(file_stream(file_name), delimiter=',', usecols=(0, 2, 3), skiprows=1)
      print('the loaded data')
      print(data.shape)
      print(data)
  
  
  if __name__ == '__main__':
      demo_use()
  
subject: Use a generator with numpy.loadtxt