If I have a nested dictionary I can get a key by indexing like so:
>>> d = {'a':{'b':'c'}} >>> d['a']['b'] 'c'
Am I able to pass that indexing as a function parameter?
def get_nested_value(d, path=['a']['b']): return d[path]
Obviously, this is incorrect, I get TypeError: list indices must be integers, not str
.
How can I do it correctly?
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Answer
You can use reduce
(or functools.reduce
in python 3), but that would also require you to pass in a list/tuple of your keys:
>>> def get_nested_value(d, path=('a', 'b')): return reduce(dict.get, path, d) >>> d = {'a': {'b': 'c'}} >>> get_nested_value(d) 'c' >>>
(In your case ['a']['b']
doesn’t work because ['a']
is a list, and ['a']['b']
is trying to look up the element at “b“th index of that list)