code: 
  
  
  
  
  
  
  class 				_lowerCamelCase :
  
  
  
        """simple docstring"""
  
  
  
  
  
  
        def __init__( self				,						UpperCAmelCase   )       ->   List[Any]:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          __snake_case   :				List[Any]        =       data
          __snake_case   :				str        =       None
          __snake_case   :				int        =       None
  
  
  
  
  
  
  
        def __str__( self   )       ->   str:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          return F"""{self.data}"""
  
  
  
  
  class 				_lowerCamelCase :
  
  
  
        """simple docstring"""
  
  
  
  
  
  
        def __init__( self   )       ->   Any:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          __snake_case   :				str        =       None
          __snake_case   :				Any        =       None
  
  
  
  
  
  
  
        def __iter__( self   )       ->   int:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          __snake_case   :				Optional[Any]        =       self.head
          while node:
            yield node.data
            __snake_case   :				str        =       node.next
  
  
  
  
  
  
  
        def __str__( self   )       ->   Union[str, Any]:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          return "->".join([str(UpperCAmelCase   ) for item in self]   )
  
  
  
  
  
  
  
        def __len__( self   )       ->   str:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          return sum(1 for _ in self   )
  
  
  
  
  
  
  
        def 						UpperCAmelCase		( self				,						UpperCAmelCase   )       ->   Any:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          self.insert_at_nth(0				,						UpperCAmelCase   )
  
  
  
  
  
  
  
        def 						UpperCAmelCase		( self				,						UpperCAmelCase   )       ->   Optional[Any]:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          self.insert_at_nth(len(self   )				,						UpperCAmelCase   )
  
  
  
  
  
  
  
        def 						UpperCAmelCase		( self				,						UpperCAmelCase				,						UpperCAmelCase   )       ->   Optional[Any]:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          __snake_case   :				Optional[int]        =       len(self   )
  
          if not 0 <= index <= length:
            raise IndexError("list index out of range"   )
          __snake_case   :				Dict        =       Node(UpperCAmelCase   )
          if self.head is None:
            __snake_case   :				Dict        =       new_node
          elif index == 0:
            __snake_case   :				int        =       new_node
            __snake_case   :				Optional[int]        =       self.head
            __snake_case   :				List[Any]        =       new_node
          elif index == length:
            __snake_case   :				Optional[int]        =       new_node
            __snake_case   :				str        =       self.tail
            __snake_case   :				Any        =       new_node
          else:
            __snake_case   :				List[str]        =       self.head
            for _ in range(0				,						UpperCAmelCase   ):
              __snake_case   :				Optional[int]        =       temp.next
            __snake_case   :				List[str]        =       new_node
            __snake_case   :				Optional[Any]        =       temp.previous
            __snake_case   :				str        =       temp
            __snake_case   :				Tuple        =       new_node
  
  
  
  
  
  
  
        def 						UpperCAmelCase		( self   )       ->   List[Any]:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          return self.delete_at_nth(0   )
  
  
  
  
  
  
  
        def 						UpperCAmelCase		( self   )       ->   List[Any]:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          return self.delete_at_nth(len(self   ) - 1   )
  
  
  
  
  
  
  
        def 						UpperCAmelCase		( self				,						UpperCAmelCase   )       ->   Optional[int]:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          __snake_case   :				Optional[Any]        =       len(self   )
  
          if not 0 <= index <= length - 1:
            raise IndexError("list index out of range"   )
          __snake_case   :				Tuple        =       self.head  # default first node
          if length == 1:
            __snake_case   :				int        =       None
          elif index == 0:
            __snake_case   :				List[str]        =       self.head.next
            __snake_case   :				List[str]        =       None
          elif index == length - 1:
            __snake_case   :				Tuple        =       self.tail
            __snake_case   :				Union[str, Any]        =       self.tail.previous
            __snake_case   :				str        =       None
          else:
            __snake_case   :				Any        =       self.head
            for _ in range(0				,						UpperCAmelCase   ):
              __snake_case   :				Optional[Any]        =       temp.next
            __snake_case   :				int        =       temp
            __snake_case   :				Dict        =       temp.previous
            __snake_case   :				List[str]        =       temp.next
          return delete_node.data
  
  
  
  
  
  
  
        def 						UpperCAmelCase		( self				,						UpperCAmelCase   )       ->   str:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          __snake_case   :				Optional[Any]        =       self.head
  
          while current.data != data:  # Find the position to delete
            if current.next:
              __snake_case   :				Optional[Any]        =       current.next
            else:  # We have reached the end an no value matches
              raise ValueError("No data matching given value"   )
  
          if current == self.head:
            self.delete_head()
  
          elif current == self.tail:
            self.delete_tail()
  
          else:  # Before: 1 <--> 2(current) <--> 3
            __snake_case   :				Dict        =       current.next  # 1 --> 3
            __snake_case   :				Optional[int]        =       current.previous  # 1 <--> 3
          return data
  
  
  
  
  
  
  
        def 						UpperCAmelCase		( self   )       ->   Any:
  
  
  
  
  
  
          '''simple docstring'''
  
  
  
  
  
  
          return len(self   ) == 0
  
  
  
  
  
  
  
  def       lowerCAmelCase__(	) ->    None:
    __snake_case   :				Any        =       DoublyLinkedList()
    assert linked_list.is_empty() is True
    assert str(__lowerCamelCase				) == ""
  
    try:
      linked_list.delete_head()
      raise AssertionError  # This should not happen.
    except IndexError:
      assert True  # This should happen.
  
    try:
      linked_list.delete_tail()
      raise AssertionError  # This should not happen.
    except IndexError:
      assert True  # This should happen.
  
    for i in range(10				):
      assert len(__lowerCamelCase				) == i
      linked_list.insert_at_nth(__lowerCamelCase   ,     i + 1				)
    assert str(__lowerCamelCase				) == "->".join(str(__lowerCamelCase				) for i in range(1   ,     11				)				)
  
    linked_list.insert_at_head(0				)
    linked_list.insert_at_tail(11				)
    assert str(__lowerCamelCase				) == "->".join(str(__lowerCamelCase				) for i in range(0   ,     12				)				)
  
    assert linked_list.delete_head() == 0
    assert linked_list.delete_at_nth(9				) == 10
    assert linked_list.delete_tail() == 11
    assert len(__lowerCamelCase				) == 9
    assert str(__lowerCamelCase				) == "->".join(str(__lowerCamelCase				) for i in range(1   ,     10				)				)
  
  
  if __name__ == "__main__":
       from doctest import testmod
  
       testmod()
  
  
style_context: 
  
  
  
  
  
  from typing import TYPE_CHECKING
  
  from ...utils import OptionalDependencyNotAvailable, _LazyModule, is_torch_available, is_vision_available
  
  
  _UpperCamelCase       = {
      '''configuration_deta''': ['''DETA_PRETRAINED_CONFIG_ARCHIVE_MAP''', '''DetaConfig'''],
  }
  
  try:
       if not is_vision_available():
            raise OptionalDependencyNotAvailable()
  except OptionalDependencyNotAvailable:
       pass
  else:
       _UpperCamelCase       = ['''DetaImageProcessor''']
  
  try:
       if not is_torch_available():
            raise OptionalDependencyNotAvailable()
  except OptionalDependencyNotAvailable:
       pass
  else:
       _UpperCamelCase       = [
           '''DETA_PRETRAINED_MODEL_ARCHIVE_LIST''',
           '''DetaForObjectDetection''',
           '''DetaModel''',
           '''DetaPreTrainedModel''',
       ]
  
  
  if TYPE_CHECKING:
       from .configuration_deta import DETA_PRETRAINED_CONFIG_ARCHIVE_MAP, DetaConfig
  
       try:
            if not is_vision_available():
                 raise OptionalDependencyNotAvailable()
       except OptionalDependencyNotAvailable:
            pass
       else:
            from .image_processing_deta import DetaImageProcessor
  
       try:
            if not is_torch_available():
                 raise OptionalDependencyNotAvailable()
       except OptionalDependencyNotAvailable:
            pass
       else:
            from .modeling_deta import (
                DETA_PRETRAINED_MODEL_ARCHIVE_LIST,
                DetaForObjectDetection,
                DetaModel,
                DetaPreTrainedModel,
            )
  
  else:
       import sys
  
       _UpperCamelCase       = _LazyModule(__name__, globals()['''__file__'''], _import_structure, module_spec=__spec__)
  
  