Access dict key and return None if doesn't exist

Question

In Python what is the most efficient way to do this:

my_var = some_var[\'my_key\'] | None

ie. assign some_var[\'my_key\'] to

Answer 1

For a new dict:

from collections import defaultdict
# None is the default, but you can change this default value
d = defaultdict(lambda: None)

For an existing dict:

from collections import defaultdict
# convert a dictionary to a defaultdict
d = defaultdict(lambda: None,d)