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ChainMap v Pythonu

Python vsebuje vsebnik z imenom ' ChainMap ', ki zajema mnoge slovarji v eno enoto. ChainMap je član modula ' zbirke '. primer: Python3 
# Python program to demonstrate  # ChainMap  from collections import ChainMap d1 = {'a': 1 'b': 2} d2 = {'c': 3 'd': 4} d3 = {'e': 5 'f': 6} # Defining the chainmap  c = ChainMap(d1 d2 d3) print(c)
Izhod: 
ChainMap({'a': 1 'b': 2} {'c': 3 'd': 4} {'e': 5 'f': 6})
Oglejmo si različne operacije na ChainMap

Operacije dostopa

    ključi() :-Ta funkcija se uporablja za prikaz vseh ključi vseh slovarjev v ChainMap. vrednosti() :-Ta funkcija se uporablja za prikaz vrednosti vseh slovarjev v ChainMap. zemljevidi() :-Ta funkcija se uporablja za prikaz ključi z ustreznimi vrednostmi vseh slovarjev v ChainMap.
Python3 
# Please select Python 3 for running this code in IDE # Python code to demonstrate ChainMap and # keys() values() and maps # importing collections for ChainMap operations import collections # initializing dictionaries dic1 = { 'a' : 1 'b' : 2 } dic2 = { 'b' : 3 'c' : 4 } # initializing ChainMap chain = collections.ChainMap(dic1 dic2) # printing chainMap using maps print ('All the ChainMap contents are : ') print (chain.maps) # printing keys using keys() print ('All keys of ChainMap are : ') print (list(chain.keys())) # printing keys using keys() print ('All values of ChainMap are : ') print (list(chain.values()))
Izhod: 
All the ChainMap contents are : [{'b': 2 'a': 1} {'c': 4 'b': 3}] All keys of ChainMap are : ['a' 'c' 'b'] All values of ChainMap are : [1 4 2]
  Opomba: Upoštevajte, da ključ z imenom 'b' obstaja v obeh slovarjih, vendar je samo prvi slovarski ključ vzet kot ključna vrednost 'b'. Urejanje poteka, ko so slovarji posredovani v funkciji.

Manipuliranje operacij

    new_child() :-Ta funkcija doda nov slovar na začetek ChainMap. obrnjeno() :-Ta funkcija obrne relativno vrstni red slovarjev v ChainMap.
Python3 
# Please select Python 3 for running this code in IDE # Python code to demonstrate ChainMap and # reversed() and new_child() # importing collections for ChainMap operations import collections # initializing dictionaries dic1 = { 'a' : 1 'b' : 2 } dic2 = { 'b' : 3 'c' : 4 } dic3 = { 'f' : 5 } # initializing ChainMap chain = collections.ChainMap(dic1 dic2) # printing chainMap using map print ('All the ChainMap contents are : ') print (chain.maps) # using new_child() to add new dictionary chain1 = chain.new_child(dic3) # printing chainMap using map print ('Displaying new ChainMap : ') print (chain1.maps) # displaying value associated with b before reversing print ('Value associated with b before reversing is : 'end='') print (chain1['b']) # reversing the ChainMap chain1.maps = reversed(chain1.maps) # displaying value associated with b after reversing print ('Value associated with b after reversing is : 'end='') print (chain1['b'])
Izhod: 
All the ChainMap contents are : [{'b': 2 'a': 1} {'b': 3 'c': 4}] Displaying new ChainMap : [{'f': 5} {'b': 2 'a': 1} {'b': 3 'c': 4}] Value associated with b before reversing is : 2 Value associated with b after reversing is : 3