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If you treat dictionaries as sets of tuples union doesn’t work as expected: {(‘a’,1)} | {(‘a’, 2)} = {(‘a’,1), (‘a’, 2)} Same key maps two values.

• deleted 8y ago
  [deleted]
• coldtea 8y ago
  That's not what the parent says though. He says that sets are like dictionaries without values, e.g. a set is akin to the dictionary keys. So, in your example the ('a', 1) and ('a', 2) are the keys (in how the parent argues about) -- it's not 'a' that's the key. Same like you can do today: d = {} d[('a', 1)] = 6 d[('a', 2)] = 89 We can still express that dictionary as a set of tuples, it's just: {(('a', 1), 6), (('a', 2), 89)}
  • 103e 8y ago
    Meant to respond to top level parent who said: > dicts would subclass sets Was trying to make the case as to why treating dictionaries as a child of <generic collection> with an extend/merge operation using ‘+’ rather than a child of set with a union operation ‘|’ makes more sense (to me). Changing the behaviour of a well defined operation like union seems bad - although my case is somewhat undermined by python’s overloading of ‘+’ to mean extend.