from __future__ import annotations

from collections.abc import Iterable
from dataclasses import dataclass
from typing import Any



class 			UpperCamelCase					:

     '''simple docstring'''

     A_					    =	('_front', '_back', '_len')



     @dataclass
     class 			UpperCamelCase					:

          '''simple docstring'''

          A_					    =	None
          A_					    =	None
          A_					    =	None





     class 			UpperCamelCase					:

          '''simple docstring'''

          A_					    =	('_cur',)



          def __init__(       self					,					A_    )			->					None:






                """simple docstring"""
                _lowerCamelCase           =					cur



          def __iter__(       self    )			->					Deque._Iterator:






                """simple docstring"""
                return self





          def 		UpperCamelCase_    (       self    )			->					Any:






                """simple docstring"""
                if self._cur is None:
                      # finished iterating
                      raise StopIteration
                _lowerCamelCase           =					self._cur.val
                _lowerCamelCase           =					self._cur.next_node

                return val





     def __init__(       self					,					A_ = None    )			->					None:






           """simple docstring"""
           _lowerCamelCase           =					None
           _lowerCamelCase           =					None
           _lowerCamelCase           =					0

           if iterable is not None:
                 # append every value to the deque
                 for val in iterable:
                       self.append(A_    )



     def 		UpperCamelCase_    (       self					,					A_    )			->					None:






           """simple docstring"""
           _lowerCamelCase           =					self._Node(A_					,					A_					,					A_    )
           if self.is_empty():
                 # front = back
                 _lowerCamelCase           =					_lowerCamelCase           =					node
                 _lowerCamelCase           =					1
           else:
                 # connect nodes
                 _lowerCamelCase           =					node
                 _lowerCamelCase           =					self._back
                 _lowerCamelCase           =					node  # assign new back to the new node

                 self._len += 1

                 # make sure there were no errors
                 assert not self.is_empty(), "Error on appending value."



     def 		UpperCamelCase_    (       self					,					A_    )			->					None:






           """simple docstring"""
           _lowerCamelCase           =					self._Node(A_					,					A_					,					A_    )
           if self.is_empty():
                 # front = back
                 _lowerCamelCase           =					_lowerCamelCase           =					node
                 _lowerCamelCase           =					1
           else:
                 # connect nodes
                 _lowerCamelCase           =					self._front
                 _lowerCamelCase           =					node
                 _lowerCamelCase           =					node  # assign new front to the new node

                 self._len += 1

                 # make sure there were no errors
                 assert not self.is_empty(), "Error on appending value."



     def 		UpperCamelCase_    (       self					,					A_    )			->					None:






           """simple docstring"""
           for val in iterable:
                 self.append(A_    )



     def 		UpperCamelCase_    (       self					,					A_    )			->					None:






           """simple docstring"""
           for val in iterable:
                 self.appendleft(A_    )



     def 		UpperCamelCase_    (       self    )			->					Any:






           """simple docstring"""
           assert not self.is_empty(), "Deque is empty."

           _lowerCamelCase           =					self._back
           _lowerCamelCase           =					self._back.prev_node  # set new back
           # drop the last node - python will deallocate memory automatically
           _lowerCamelCase           =					None

           self._len -= 1

           return topop.val



     def 		UpperCamelCase_    (       self    )			->					Any:






           """simple docstring"""
           assert not self.is_empty(), "Deque is empty."

           _lowerCamelCase           =					self._front
           _lowerCamelCase           =					self._front.next_node  # set new front and drop the first node
           _lowerCamelCase           =					None

           self._len -= 1

           return topop.val



     def 		UpperCamelCase_    (       self    )			->					bool:






           """simple docstring"""
           return self._front is None



     def __len__(       self    )			->					int:






           """simple docstring"""
           return self._len



     def __eq__(       self					,					A_    )			->					bool:






           """simple docstring"""

           if not isinstance(A_					,					A_    ):
                 return NotImplemented

           _lowerCamelCase           =					self._front
           _lowerCamelCase           =					other._front

           # if the length of the dequeues are not the same, they are not equal
           if len(self    ) != len(A_    ):
                 return False

           while me is not None and oth is not None:
                 # compare every value
                 if me.val != oth.val:
                       return False
                 _lowerCamelCase           =					me.next_node
                 _lowerCamelCase           =					oth.next_node

           return True



     def __iter__(       self    )			->					Deque._Iterator:






           """simple docstring"""
           return Deque._Iterator(self._front    )





     def __repr__(       self    )			->					str:






           """simple docstring"""
           _lowerCamelCase           =					[]
           _lowerCamelCase           =					self._front
           while aux is not None:
                 # append the values in a list to display
                 values_list.append(aux.val    )
                 _lowerCamelCase           =					aux.next_node

           return F'[{", ".join(repr(A_    ) for val in values_list    )}]'


if __name__ == "__main__":
     import doctest

     doctest.testmod()
import torch

from accelerate import Accelerator, DistributedType



class 			UpperCamelCase					:

     '''simple docstring'''

     def __enter__(       self    )			->					int:






           """simple docstring"""
           if self.enabled:
                 _lowerCamelCase           =					self.model.no_sync()
                 self.model_sync_obj.__enter__()

           return self



     def __exit__(       self					,					A_					,					A_					,					A_    )			->					Union[str, Any]:






           """simple docstring"""
           if self.enabled:
                 # Average all models on exit
                 self._sync_and_avg_model_params()
                 self.model_sync_obj.__exit__(A_					,					A_					,					A_    )



     def __init__(       self					,					A_					,					A_					,					A_					,					A_ = True    )			->					List[str]:






           """simple docstring"""
           if accelerator.distributed_type not in [
               DistributedType.NO,
               DistributedType.MULTI_CPU,
               DistributedType.MULTI_GPU,
           ]:
                 raise NotImplementedError('''LocalSGD is supported only for CPUs and GPUs (no DeepSpeed or MegatronLM)'''    )
           _lowerCamelCase           =					enabled and accelerator.distributed_type != DistributedType.NO
           _lowerCamelCase           =					0
           if self.enabled:
                 _lowerCamelCase           =					accelerator
                 _lowerCamelCase           =					model
                 _lowerCamelCase           =					local_sgd_steps



     def 		UpperCamelCase_    (       self    )			->					Optional[Any]:






           """simple docstring"""
           self.num_steps += 1
           if not self.enabled:
                 return

           if self.num_steps % self.local_sgd_steps == 0:
                 self._sync_and_avg_model_params()





     def 		UpperCamelCase_    (       self    )			->					Union[str, Any]:






           """simple docstring"""
           self.accelerator.wait_for_everyone()
           with self.accelerator.autocast():
                 for param in self.model.parameters():
                       _lowerCamelCase           =					self.accelerator.reduce(param.data					,					reduction='''mean'''    )