from collections import ChainMap

# Chain dictionaries with ChainMap
for_adoption = {"dogs": 18, "cats": 7, "pythons": 3}
vet_treatment = {"hamsters": 2, "turtles": 1}


print(ChainMap(for_adoption, vet_treatment))


# Merge dictionaries with .update()
pets = {}

pets.update(for_adoption)

pets.update(vet_treatment)

print(pets)