old_contents: import unittest
  import base64
  import os
  from os.path import join, dirname, abspath
  
  
  class IOTest(unittest.TestCase):
      def test_read_try(self):
          try:
              file = open(join(dirname(__file__), '../README.md'), 'r')
              self.assertGreater(len(file.read()), 10)
          except Exception as e:
              print(e)
  
      def test_read_context(self):
          with open(join(dirname(__file__), '../README.md'), 'r') as file:
              self.assertGreater(len(file.read()), 10)
  
      def test_data_url(self):
          with open(join(dirname(__file__), '../cat_rocket.jpg'), 'rb') as file:
              image_date = file.read()
              base64_data = base64.b64encode(image_date)
  
              # 可以在浏览器里打开这个 url
              data_url = 'data:image/jpg;base64,' + str(base64_data, 'ascii')
  
              self.assertGreater(len(data_url), 100)
  
      def test_walk(self):
          def inspect(filename):
              print(filename)
  
          files = os.walk(abspath(join(dirname(__file__), '../')))
  
          l = [dirpath for dirpath, dirname, filenames in files]
  
          self.assertGreater(len(l), 0)
  
new_contents: import unittest
  import base64
  import os
  from os.path import join, dirname, abspath
  
  
  class IOTest(unittest.TestCase):
      def test_read_try(self):
          try:
              file = open(join(dirname(__file__), '../README.md'), 'r')
              self.assertGreater(len(file.read()), 10)
          except Exception as e:
              print(e)
          finally:
              if file:
                  file.close()
  
      def test_read_context(self):
          with open(join(dirname(__file__), '../README.md'), 'r') as file:
              self.assertGreater(len(file.read()), 10)
  
      def test_data_url(self):
          with open(join(dirname(__file__), '../cat_rocket.jpg'), 'rb') as file:
              image_date = file.read()
              base64_data = base64.b64encode(image_date)
  
              # 可以在浏览器里打开这个 url
              data_url = 'data:image/jpg;base64,' + str(base64_data, 'ascii')
  
              self.assertGreater(len(data_url), 100)
  
      def test_walk(self):
          def inspect(filename):
              print(filename)
  
          files = os.walk(abspath(join(dirname(__file__), '../')))
  
          l = [dirpath for dirpath, dirname, filenames in files]
  
          self.assertGreater(len(l), 0)
  
subject: fix warning