python - How to get a value from a nested dict?

Question

Is there an easy, concise way to get a value from a nested dict and get None if it's not there?

d1 = None
d2 = {}
d3 = {"a": {}}
d4 = {"a": {"b": 12345}}
ds = [d1, d2, d3, d4]


def nested_get(d):
    # Is there a simpler concise one-line way to do exactly this, query a nested dict value, and return None if
    # it doesn't exist?
    a_val = d.get("a") if d else None
    b_val = a_val.get("b") if a_val else None
    return b_val

if __name__ == "__main__":
    bs = [nested_get(d) for d in ds]
    print("bs={}".format(bs))

Answer 1

This should work:

def nested_get(d, *keys):
    for key in keys:
        if d is None:
            break
        d = d.get(key)
    return d