UUID and secrets module

1.uuid What is it? ？

UUID yes Universally Unique IDentifier( Universally unique identification )

UUID Represents the universal unique identifier , It's a 128 The value of a , Unique identification for software development

UUID The generation of is based on the current timestamp and the generation UUID Unique attribute of workstation

2.UUID The classification of

• uuid1

  uuid.uuid1([node[,clock_seq]]): Based on timestamps 
  """  Use the host ID, Serial number and current time to generate UUID, It guarantees global uniqueness , But because this method generates UUID Contains the network address of the host , May endanger privacy   If node Parameter default , The system automatically calls getnode() Function to get the hardware address of the host   If clock_seq default , Then randomly 14 Bit serial number instead  """
  

• uuid4

  uuid.uuid4(): Based on random numbers 
  '''  Generate by random numbers uuid, But the pseudo-random number used has a certain repetition probability  '''
  

• uuid3

  uuid.uuid3(namespace,name): Based on name MD5 Hash value 
  '''  By calculating the name of the namespace and MD5 Hash values to generate uuid, It can guarantee the uniqueness of different names in the same namespace and the uniqueness of different namespace  '''
  uuid.uuid3(uuid.NAMESPACE_DNS,'456')
  

• uuid5

  uuid.uuid3(namespace,name): Based on name SHA-1 Hash value 
  '''  By calculating the name of the namespace and SHA-1 Hash value generation uuid, Algorithm and uuid3 identical  '''
  uuid.uuid5(uuid.NAMESPACE_DNS,'456')
  

3. What is? Secrets

secrets yes python3.6 Added to the standard library , Use secrets modular , Can be generated for processing confidential information （ Such as password , Account authentication , Security Token ） Of encryption Strong random number .

Common functions	explain	example
choice(sequence)	Select an element from a non empty sequence	secrets.choice([23,3,5,6])
randbelow(n)	Random one [0,n) The integer of	secrets.randbelow(10)
randbits(n)	stay n Bit length random one bit in the range of binary numbers	secrets.randbits(10)
token_bytes(n)	Random generation n Within bytes bytes Type string	secrets.token_bytes(2)
token_hex(n)	return n Bit length 16 Hexadecimal random text string	secrets.token_hex(2)
taken_urlsafa(n)	The returned bytes are nbytes Of URL Secure text string . The text is written with Base64 code , Each byte averages about 1.3 Characters .	secrets.token_urlsafe()
compare_digest(str,str)	String comparison , Equal return True	secrets.compare_digest(‘a’,‘a’)