A brief introduction to the method of pickling module to package and unpackage data objects from python series

Encapsulation is a process of converting Python data objects into byte streams. Unpacking is the reverse operation of encapsulation, which transfers bytes from byte files or byte objects to Python data objects. Do not unpack data from trusted data sources. Can encapsulate and unwrap almost any Python data object, mainly including:

      None, True, False
      Integers, floating point Numbers, complex Numbers
      String, byte, ByteArray object
      Tuples, lists, collections, dictionaries containing encapsulated objects
      Functions defined at the top of a module
      A built-in function defined at the top of a module
      That's the class defined at the top of a module
      The result of either calling/s/s/s/s/s/s/s/s/s/s/s/s/s/s/s/s/s is an instance of the encapsulated class

  The methods commonly used in the pickle module are:

      1. Pickling. Dump (obj file, protocol = None,)

      The required parameter obj represents the object to be encapsulated

      The required parameter file represents the file object to be written by obj. The file must be opened in binary writable mode, i.e. "wb"

      Protocol, an optional parameter, tells pickler which protocol to use. The supported protocol is 0,1,2, and 3. The default protocol is protocol 3 added to Python 3.         See the documentation for further agreement details

      2. Pickling. The load (file, *, fix_imports = True, encoding = "ASCII", errors = "strict")

      The required parameter file must be opened in binary readable mode, that is, "rb", and everything else is optional

      3. Pickle. Dumps (obj) : the encapsulated object is returned as a byte object and does not need to be written to a file

      Pickle. Loads (bytes_object): reads the encapsulated object from the byte object and returns

  There are three possible exceptions to the pickle module:

      1. PickleError: an Exception class that occurs when packaging and unpacking, inherited from Exception

      2. PicklingError: an exception that occurs when an unencapsulated object is encountered, inherited from PickleError

      3. UnPicklingError: an exception in the process of unsealing an object, inherited from PickleError

  Application examples of pickle:

import pickle  
with open("my_profile.txt", "wb") as myprofile:  
    pickle.dump({"name":"AlwaysJane", "age":"20+", "sex":"female"}, myprofile)
with open("my_profile.txt", "rb") as get_myprofile:
    print (pickle.load(get_myprofile))

import pickle 
class Profile:
    name = "AlwaysJane"
pickledclass = pickle.dumps(Profile)
print (pickledclass)
print (pickle.loads(pickledclass))

Understanding is not very thorough, I hope the gods correct mistakes...

Attach (link: https://docs.python.org/3.3/library/pickle.html)