getting unnecessary-dict-index-lookup when deleting an item by value

[2bndy5]

I was wondering if I'm doing this wrong. I'm trying to remove a dict item when searching the dict's items() to re-assign a certain unique value to a new key.

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NOTES

1. The dict I'm managing is a private class member and will not have multiple keys with the same value.
2. I'm using pylint v2.9.3 (had the same problem with v2.9.0 previously)

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I've added # pylint: comments around the controversial line

    def _set_address(self, node_id, address, search_by_address=False):
        """Set or change a node_id and network address pair on the master node."""
        for n_id, addr in self._addr_dict.items():
            if not search_by_address:  # search by key
                if n_id == node_id:
                    self._addr_dict[n_id] = address
                    break
            else:  # search by value
                if addr == address:
                    # pylint: disable=unnecessary-dict-index-lookup
                    del self._addr_dict[n_id]
                    # pylint: enable=unnecessary-dict-index-lookup
                    self._addr_dict[node_id] = address
                    break
        if node_id not in self._addr_dict.keys():
            self._addr_dict[node_id] = address

The pylint message suggests I use addr instead, but that doesn't help when deleting an item by key.

[Pierre-Sassoulas]

Thank you for opening the issue, I think it's a false positive.

[2bndy5]

I was able to work around this in a separate instance by using dict comprehension.

new_dict = {}
for k, v in old_dict.items():
    if v != val_to_remove:
        new_dict[k] = v
old_dict = new_dict

But, applying this workaround to the snippet in the OP would be more work than its worth because I'm also re-assigning the previously used value to a new key.

[cdce8p]

This is a false-positive, unnecessary-dict-index-lookup should not be emitted for del statements.
I'm able to reproduce the error with this snipped:

d = {}
for key, val in d.items():
    del d[key]
    break

/CC: @yushao2

--
Update
The code only works if the del is followed by break. Otherwise Python would raise a Runtime error.

RuntimeError: dictionary keys changed during iteration

[yushao2]

Thanks, assigned myself to look into this