python - Class retains previous content where new instance is expected -

I define a square, and a function that creates an example of that class I thought that this function Every time a new example should be made, however, it seems that it "Inherits" its content from the previous call. Can anyone explain this? Thanks! Class test: a = [] def B (self, x): self.a.append (x) def add (): t = test () TB (2) returns a print Plus (). A

Output:

  [2] [2, 2] [2, 2, 2]    
 
 
 Here is how the definition of  a  example variable should be shown:  
  Class test (object): def __init __ (self): self.a = []   
 The way it was before  a  is the form of frequency variable , But a class variable which was being shared in all instances of the class.