Add PyDict #15
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Add PyDict #15
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delta003
reviewed
Sep 4, 2023
| /// Insert val into the dictionary p with a key of key. | ||
| /// The dictionary takes ownership of the value. | ||
| pub fn setOwnedItem(self: PyDict, key: py.PyObject, value: py.PyObject) !void { | ||
| defer value.decref(); |
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It's not clear to me how this value continues to exist after you decref it at the end of this call? SetItem https://docs.python.org/3/c-api/dict.html#c.PyDict_SetItem says "This function does not steal a reference to val.". Can you explain?
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Internally to the SetItem call both the key and value are incref'd - this is what it means by not stealing. If it were to steal, it wouldn't incref and it would assume it now owns the reference.
Because of this both the caller (us) and the dictionary have valid references to the object. So as the caller, we decref so the only reference remaining is that inside the dictionary.
delta003
approved these changes
Sep 4, 2023
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