A `getter` that brings JavaScript-style danger to Python.

getter.py

import operator
from functools import reduce


def get(obj, key):
    """Get the item within `obj` corresponding to `key`. 
    If `obj` is subscriptable, return `obj[key]`, otherwise assume `key` 
    refers to an attribute and return `obj.key` instead.
    """
    if hasattr(obj, '__getitem__'):
        return obj[key]
    else:
        return getattr(obj, key)

def getter(*keys):
    """Returns a callable object that behaves like `operator.itemgetter`, except
    that it falls back to getting attributes if the object is not subscriptable."""
    if len(keys) == 1:
        key = keys[0]
        def g(obj):
            if hasattr(obj, '__getitem__'):
                return obj[key]
            else:
                return getattr(obj, key)
    elif keys:
        def g(obj):
            ret = []
            for key in keys:
                if hasattr(obj, '__getitem__'):
                    ret.append(obj[key])
                else:
                    ret.append(getattr(obj, key))
            return tuple(ret)
    return g

def get_in(keys: Sequence, obj, default=None, no_default=False):
    """Get the object specified by `keys`."""
    try:
        return reduce(get, keys, obj)
    except (KeyError, IndexError, TypeError) as e:
        if no_default:
            raise e
        else:
            return default