Python Web Framework Enterprise actual combat (sixth issue) \ Second Class-pickle&__eq__

1, Python value passing and reference passing differences, what type values are passed, and which are reference passes? Value passing and reference passing differences: depending on whether the object is mutable and different from other languages, Python does not allow programmers to choose to pass a value or pass a reference when passing parameters. Python parameter passing is definitely a way to "pass an object reference". In fact, this approach is equivalent to a synthesis of value-passing and reference. If a function receives a reference to a mutable object (such as a dictionary or a list), it can modify the original value of the object-the equivalent of passing the object through a "pass reference". If a function receives a reference to an immutable object (such as a number, character, or tuple), it cannot directly modify the original object-the equivalent of passing the object through a "pass value". Python is a general internal assignment variable, it is to pass a reference variable, and the C language is similar to the concept of the address. The memory address can be queried with ID () if a=b, the address of A and B is the same; if you just want to copy it, you have to use a=b[:]. #-*-coding:cp936-*-#值传递def F1 (aa): Aa=1 print "id (aa) =", id (AA) print AA bb=123print "id (bb) =", id (BB) F1 ( BB) Print bb# Reference pass def f2 (AA): aa[0]=[1] print "id (aa) =", id (AA) print AA bb=[123]print "id (bb) =", id (BB) f2 (BB) pr int bb>>> ID (bb) = 30778664id (aa) = 307781441123id (BB) = 44761936id (aa) = 44761936[[1]][[1]]>>>2, Use Python to write a command program that stores information about a number of user members that users can view only after they log in. That is: The user launches the Python script, and then enter the user name password login successfully, use the command to view other user information #-*-coding:cp936-*-class MyUser (object): Def __init__ (Self,username, Password): Self.username=username self.password=password def __del__ (self): Pass def __sTr__ (self): return str (' username=%s,password=%s '% (Self.username,self.password)) def __eq__ (Self,other): Return self.username==other.username and Self.password==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 input your password: ') curuser=myuser (Username,password) if curuser in users:for user in Users:print u ser>>> Please input your username:testplease input your password:123username=karliao,password=123456username =test,password=123>>> ================================ RESTART ================================>> > Please input your username:testplease input your Password:111>>>--eof-- 

Python Web Framework Enterprise actual combat (sixth issue) \ Second Class-pickle&__eq__