Does there exist a way in Python 2.7+ to make something like the following?
{ something_if_true if condition else something_if_false for key, value in d
In case you have different conditions to evaluate for keys and values, @Marcin's answer is the way to go.
If you have the same condition for keys and values, you're better off with building (key, value)-tuples in a generator-expression feeding into dict()
:
dict((modify_k(k), modify_v(v)) if condition else (k, v) for k, v in dct.items())
It's easier to read and the condition is only evaluated once per key, value.
Example with borrowing @Cleb's dictionary of sets:
d = {'key1': {'a', 'b', 'c'}, 'key2': {'foo', 'bar'}, 'key3': {'so', 'sad'}}
Assume you want to suffix only keys
with a
in its value
and you want the value
replaced with the length of the set in such a case. Otherwise, the key-value pair should stay unchanged.
dict((f"{k}_a", len(v)) if "a" in v else (k, v) for k, v in d.items())
# {'key1_a': 3, 'key2': {'bar', 'foo'}, 'key3': {'sad', 'so'}}