4 ms·

What happens to duplicate keys?

• dave_sullivan 9y ago
  I think it raises an exception. https://www.python.org/dev/peps/pep-0448/ https://www.python.org/dev/peps/pep-0448/ EDIT: yeah, nvm, it's what everyone else said.
  • skrause 9y ago
    No it doesn't, you simply get the value from the last dict: >>> a = {'x': 1} >>> b = {'x': 2} >>> {**a, **b} {'x': 2} >>> {**b, **a} {'x': 1}
• Kpourdeilami 9y ago
  They get overwritten by the value of the dictionary that came last. >>> dict1 = {"key1": 1, "key2": "hello", "key3": [1, 2, 3]} >>> dict2 = {key1": 1, "key2": "world", "key3": [1, 4], "key4": "4"} >>> {**dict1, **dict2} {'key1': 1, 'key2': 'world', 'key3': [1, 4], 'key4': '4'}
  • ericfrederich 9y ago
    Lots of code to show that. How 'bout this: ;-) >>> {**{'a': 'first'}, **{'a': 'second'}} {'a': 'second'}
• masklinn 9y ago
  Last pair wins, same as setting an existing key or doing an update() with an existing key.