Question

How to create new instance of ChainMap and add one more dictionary in Python

Answer 1

import collections     
 
d1 = {'a': 'AA', 'b': '***', 'c': 'CC'}
d2 = {'b': 'BB', 'f': 'GG'}     
  
cm1 = collections.ChainMap(d1, d2)     
 
cm2 = cm1.new_child()     

print('cm1:', cm1)     
print('cm2:', cm2)     
print()

cm2['b'] = 'PYTHON'
     
print('cm1:', cm1)     
print('cm2:', cm2)
 
 
 
'''
run:
 
cm1: ChainMap({'a': 'AA', 'b': '***', 'c': 'CC'}, {'b': 'BB', 'f': 'GG'})
cm2: ChainMap({}, {'a': 'AA', 'b': '***', 'c': 'CC'}, {'b': 'BB', 'f': 'GG'})

cm1: ChainMap({'a': 'AA', 'b': '***', 'c': 'CC'}, {'b': 'BB', 'f': 'GG'})
cm2: ChainMap({'b': 'PYTHON'}, {'a': 'AA', 'b': '***', 'c': 'CC'}, {'b': 'BB', 'f': 'GG'})
 
'''

 

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