old_contents: import sys
  import traceback
  
  class CustomException(Exception):
      def __init__(self, *args, **kwargs):
          super(CustomException, self).__init__(*args, **kwargs)
  
  def custom_function():
  	raise CustomException('Test to raise custom exception.')
  
  try:
      custom_function()
  except:
      _type, _value, _traceback = sys.exc_info()
      for _entry in traceback.format_tb(_traceback):
      	print(_entry)
  
new_contents: import sys
  import traceback
  
  class CustomException(Exception):
      def __init__(self, *args, **kwargs):
          super(CustomException, self).__init__(*args, **kwargs)
  
  def custom_deep_function():
  	raise CustomException('Test to raise custom exception.')
  
  def custom_function():
  	custom_deep_function()
  
  try:
      custom_function()
  except:
      _type, _value, _traceback = sys.exc_info()
      print(''.join(str(entry) for entry in traceback.format_tb(_traceback, limit=10)))
  
subject: Print stack trace of exception.