python 2.7 - Appending to a list of dictionary values list won't work -


I have a dictionary and I want to get a list of all the values ​​and one more. So I did something like this 

  new_val = 'v3' test = {'k1': 'v1', 'k2': 'v2'} l = test.values ​​(). New_val)

However when I do this, l = none . But if I use an intermediate 

  l = test.values ​​(), l.append (new_val)

l < / Code> What I need in it The first method works. 

  l = test.values ​​(). The attachment (new_val)   
  l  is none because the return value of  .append ()  (which you can call  l ) function. 
 
  l = test.values ​​() l.append (new_val)  
 
 This works because you make a copy first  A new value for test.values ​​()  and entering it into  l , and then  l  
 
 
 Add 
 
  l = test.values ​​() x = l.append (new_val)  
 
 then also  x  Is  none

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