pickle in python example

Two modules for serialization:JSON: Used to convert between string and Python data typesPickle: Converting between Python-specific types and Python data typesJSON offers four features: Dumps,dump,loads,loadPickle offers four functions: Dumps,dump,loads,loadPickle data types that can be stored All Python-suppor

The pickle module is used in Python for data persistence, and the basic usage involves both dump and load, or dumps and loads.Pickle in the use of the process has a feature, is due to its special content tag, so that file dump several times, it must load several times to read out the data, in code to show is the following form:ImportPicklea=1b=2C=3With Open ("Ceshi.txt","WB") as F:pickle.dump (a,f) pickle.d

JSON can be used between different languages, and pickle can only be used in PythonJSON cannot serialize functions, and pickle can. However, after the program uses the Pickle.dump serialization function, the memory that executes the function is freed, and the space that corresponds to the memory address read by another program with Pickle.load re-opened has been freed, so the function cannot be executed:1 #

Serialization refers to converting the data type in memory into a string so that it can be stored on the hard disk or transmitted over the network to the remote, because the hard disk or the network can only accept bytesConverting a string into an in-memory data type is called deserialization.JSON and PickleSecond, just convert the data type into a string into memory meaningJson.dumps json.loads1. Share your memory data across the network to remote others2. Define the interaction rules for diffe

\tuple\dictPickle:Pros: Designed for Python and supports all Python data typesCons: can only be used in Python, the storage data occupy large space---------------------------------------Split Line-------------------------------------------Serialization of shelve modulesimport shelvef = shelve.open(‘shelve_test‘) #打开一个文件names = [‘

==other.password import pickledir (pickle) user1=myuser (' Karli Ao ', ' 123456 ') user2=myuser (' Test ', ' 123 ') Fa=open (' E:/aa.txt ', ' W ') Pickle.dump (user1,fa,2) # #0, text form, 1,2-> Binary form pickle.dump (user2,fa,2) fa.close () fr=open (' E:/aa.txt ', ' R ') Users=[]while True:try:user=pickle.load (FR) Users.append (user) except Eoferror,e:breakusername=raw_input (' Please input your username: ') password=raw_inpu T (' Please in

,"E": 6}There is a conversion from the Python data type to the JSON type during the encoding of the JSON. Python Json Dict Object List,tuple Array Str String Int,float Number True True False False None Null ## decode>>>Encoding_json'[ [1,

Two modules for serialization:JSON: Used to convert between string and python number typesOickle: Converting between Python-specific types and Python data typesThe JSON, pickle module provides four functions: dumps, dump, loads, loadUse Jsonpickle to convert to a string to write to a file1 ImportJSON2 ImportPickle3 4 d

What is serialization?Converts an in-memory object to a linear structured string (sometimes called a byte stream) for storage or transmission. The behavior of this object into a string is often called serialization. Any data structure in memory can be mapped to a string.Serialization offunction signature#pickle.dump(objfile[, protocol])The first attempt is to serialize the Table object to a file dBASE, written in byte form:table = {‘a‘ : [123‘b‘ : [‘spam‘‘egg‘‘c‘ : {‘name‘‘Bob‘}}withopen(‘dbase‘

Python decorator use example and actual application example, python example Test 1 Deco is running, but myfunc is not running Copy codeThe Code is as follows:Def deco (func ):Print 'before func'Return func Def myfunc ():Print 'myfunc () called'Myfunc = deco (myfunc) Test 2