> Read-only proxy of a mapping. It provides a dynamic view on the mapping’s entries, which means that when the mapping changes, the view reflects these changes.
This can be helpful in some cases, but it's precisely what I sometimes need to avoid, which is protecting a dictionary and having changes affecting only its own scope.
If function A passes a dict to function B, I would like:
1) Function A to keep the dict intact while function B can manipulate its content;
2) Function A can change the dict after passing to B, and B still keep the original copy, unaware of A's later changes.
One way of doing this is by deep copying dictionaries around, but it can easily become a big performance issue.
If function A passes a dict to function B, I would like:
1) Function A to keep the dict intact while function B can manipulate its content;
2) Function A can change the dict after passing to B, and B still keep the original copy, unaware of A's later changes.
One way of doing this is by deep copying dictionaries around, but it can easily become a big performance issue.