old_contents: import datetime
  import six
  
  from decimal import Decimal
  
  from .functional import Promise
  
  
  def is_protected_type(obj):
      """Determine if the object instance is of a protected type.
  
      Objects of protected types are preserved as-is when passed to
      force_text(strings_only=True).
      """
      return isinstance(obj, six.integer_types + (type(None), float, Decimal,
                        datetime.datetime, datetime.date, datetime.time))
  
  
  def force_bytes(s, encoding='utf-8', strings_only=False, errors='strict'):
      """
      Similar to smart_bytes, except that lazy instances are resolved to
      strings, rather than kept as lazy objects.
  
      If strings_only is True, don't convert (some) non-string-like objects.
      """
      # Handle the common case first for performance reasons.
      if isinstance(s, bytes):
          if encoding == 'utf-8':
              return s
          else:
              return s.decode('utf-8', errors).encode(encoding, errors)
      if strings_only and is_protected_type(s):
          return s
      if isinstance(s, bytearray, memoryview):
          return bytes(s)
      if isinstance(s, Promise):
          return six.text_type(s).encode(encoding, errors)
      if not isinstance(s, six.string_types):
          try:
              if six.PY3:
                  return six.text_type(s).encode(encoding)
              else:
                  return bytes(s)
          except UnicodeEncodeError:
              if isinstance(s, Exception):
                  # An Exception subclass containing non-ASCII data that doesn't
                  # know how to print itself properly. We shouldn't raise a
                  # further exception.
                  return b' '.join([force_bytes(arg, encoding, strings_only,
                                                errors) for arg in s])
              return six.text_type(s).encode(encoding, errors)
      else:
          return s.encode(encoding, errors)
  
new_contents: import datetime
  import six
  
  from decimal import Decimal
  
  from .functional import Promise
  
  
  def is_protected_type(obj):
      """Determine if the object instance is of a protected type.
  
      Objects of protected types are preserved as-is when passed to
      force_text(strings_only=True).
      """
      return isinstance(obj, six.integer_types + (type(None), float, Decimal,
                        datetime.datetime, datetime.date, datetime.time))
  
  
  def force_bytes(s, encoding='utf-8', strings_only=False, errors='strict'):
      """
      Similar to smart_bytes, except that lazy instances are resolved to
      strings, rather than kept as lazy objects.
  
      If strings_only is True, don't convert (some) non-string-like objects.
      """
      # Handle the common case first for performance reasons.
      if isinstance(s, bytes):
          if encoding == 'utf-8':
              return s
          else:
              return s.decode('utf-8', errors).encode(encoding, errors)
      if strings_only and is_protected_type(s):
          return s
      if isinstance(s, (bytearray, memoryview)):
          return bytes(s)
      if isinstance(s, Promise):
          return six.text_type(s).encode(encoding, errors)
      if not isinstance(s, six.string_types):
          try:
              if six.PY3:
                  return six.text_type(s).encode(encoding)
              else:
                  return bytes(s)
          except UnicodeEncodeError:
              if isinstance(s, Exception):
                  # An Exception subclass containing non-ASCII data that doesn't
                  # know how to print itself properly. We shouldn't raise a
                  # further exception.
                  return b' '.join([force_bytes(arg, encoding, strings_only,
                                                errors) for arg in s])
              return six.text_type(s).encode(encoding, errors)
      else:
          return s.encode(encoding, errors)
  
subject: Fix Python 3 error