Prevent the same object being added more than once to a given list #1414
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by using the name `_items` for the elements of the list.
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Just one tiny question/suggestion for the error, but otherwise this looks good to me. I want to test this locally this afternoon and then I'll sign off. But I agree that biologically it really doesn't make sense to allow someone to add the exact same object multiple times.
neo/core/objectlist.py
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| @@ -32,6 +32,10 @@ def _handle_append(self, obj): | |||
| ) | |||
| ): | |||
| raise TypeError(f"Object is a {type(obj)}. It should be one of {self.allowed_contents}.") | |||
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| if self._contains(obj): | |||
| raise ValueError("Cannot add the same object twice") | |||
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Is there a way to be more descriptive here. You can add the same type of object, but not the same object. I'm just a little worried someone might get confused.
| raise ValueError("Cannot add the same object twice") | |
| raise ValueError(f"Cannot add {obj} because it is already contained within {self}") |
Not sure if that works or if you need something else.
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The string representation of data objects can be very long, so I don't think it's a good idea to put it in exception messages. How about "Cannot add this object because it is already contained within the list"?
This relates to #1405 - in the scenario in that issue, a ValueError will be raised.
(note: the change of attribute name from
contentsto_itemsis because_handle_appendis also used by SpikeTrainList, which uses the name_items).