Hello,
This is my first mail here, so greetings for everyone :)
I would like to introduce an idea of the new operators for dict objects.
Any thoughts are welcome.
Since Python3.9 there is a great feature for merging dicts using | (OR)
operator:
{1: "a"} | {2: "b"} == {1: "a", 2: "b"}
Thus, this basic operation can be done smoothly (also inline).
PEP: https://www.python.org/dev/peps/pep-0584/
Another common operation on dicts is a substitution - building a new dict with
only a part of the data. Usually the part of the data is described as a list
of keys to keep or a list of keys to skip.
Therefore it would be very handy to have a build-in option to filter out a
dict with a similar fashion, for example using & (AND) operator against a
list/tuple/set/frozenset of keys that should be kept in the result):
{1: "a", 2: "b", 3: "c"} & [1, 3, 4] == {1: "a", 3: "c"}
{1: "a", 2: "b", 3: "c"} & {1, 3, 4} == {1: "a", 3: "c"}
Using the & operator:
dict_object & list_of_keys
would be equal to the following expression:
{key: value for key, value in dict_object .items() if key in list_of_keys}
Additionally, a similar option for omitting specified keys could be done with
another - (minus) operator against a list/tuple/set/frozenset of keys that
should be suppressed):
{1: "a", 2: "b", 3: "c"} - [3, 4] == {1: "a", 2: "b"}
{1: "a", 2: "b", 3: "c"} - {3, 4} == {1: "a", 2: "b"}
Using the - operator:
dict_object - list_of_keys
would be equal to following expression:
{key: value for key, value in dict_object .items() if key not in
list_of_keys}
Best,
Tomasz
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