code: 
  
  
  
  
  
  import os
  import sys
  import time
  
  from . import transposition_cipher as trans_cipher
  
  def     a						(      )     ->None:
  		UpperCamelCase__         =	"""Prehistoric Men.txt"""
  		UpperCamelCase__         =	"""Output.txt"""
  		UpperCamelCase__         =	int(input("""Enter key: """       )       )
  		UpperCamelCase__         =	input("""Encrypt/Decrypt [e/d]: """       )
  
  		if not os.path.exists(_lowercase       ):
  				print(F"""File {input_file} does not exist. Quitting..."""       )
  				sys.exit()
  		if os.path.exists(_lowercase       ):
  				print(F"""Overwrite {output_file}? [y/n]"""       )
  				UpperCamelCase__         =	input("""> """       )
  				if not response.lower().startswith("""y"""       ):
  						sys.exit()
  
  		UpperCamelCase__         =	time.time()
  		if mode.lower().startswith("""e"""       ):
  				with open(_lowercase       ) as f:
  						UpperCamelCase__         =	f.read()
  				UpperCamelCase__         =	trans_cipher.encrypt_message(_lowercase ,						_lowercase       )
  		elif mode.lower().startswith("""d"""       ):
  				with open(_lowercase       ) as f:
  						UpperCamelCase__         =	f.read()
  				UpperCamelCase__         =	trans_cipher.decrypt_message(_lowercase ,						_lowercase       )
  
  		with open(_lowercase ,						"""w"""       ) as output_obj:
  				output_obj.write(_lowercase       )
  
  		UpperCamelCase__         =	round(time.time() - start_time ,						2       )
  		print(("""Done (""", total_time, """seconds )""")       )
  
  
  if __name__ == "__main__":
  				main()
  
  
  
  
  
  
style_context: 
  
  
  
  
  
  def     a						(      _lowercase   :     Optional[int]       )     ->List[str]:
  		UpperCamelCase__         =	len(_lowercase       )
  		for i in range(length - 1       ):
  				UpperCamelCase__         =	False
  				for j in range(length - 1 - i       ):
  						if collection[j] > collection[j + 1]:
  								UpperCamelCase__         =	True
  								UpperCamelCase__  ,			UpperCamelCase__         =	collection[j + 1], collection[j]
  				if not swapped:
  						break  # Stop iteration if the collection is sorted.
  		return collection
  
  
  if __name__ == "__main__":
  				import doctest
  				import time
  
  				doctest.testmod()
  
  				__lowerCAmelCase     =			input("Enter numbers separated by a comma:").strip()
  				__lowerCAmelCase     =			[int(item) for item in user_input.split(",")]
  				__lowerCAmelCase     =			time.process_time()
  				print(*bubble_sort(unsorted), sep=",")
  				print(f"""Processing time: {(time.process_time() - start)%1e9 + 7}""")
  
  
  
  
  
  