Combining a few things I see here.

from functools import reduce


def optional_chain(obj, keys):
    try:
        reduce(getattr, keys.split('.'), root)
    except AttributeError:
        return None

optional_chain(foo, 'bar.baz')

Or instead extend getattr so you can also use it as a drop-in replacement for getattr

from functools import reduce


def rgetattr(obj, attr, *args):
    def _getattr(obj, attr):
        return getattr(obj, attr, *args)
    return reduce(_getattr, attr.split('.'), obj)

With rgetattr it can still raise an AttributeError if the path does not exist, and you can specify your own default instead of None.

I like modern languages like Kotlin which allow this:

foo?.bar?.baz

Recently I had fun trying to implement something similar in python: https://gist.github.com/karbachinsky/cc5164b77b09170edce7e67e57f1636c

Unfortunately, the question mark is not a valid symbol in attribute names in python, thus I used a similar mark from Unicode :)

You can use the Glom.

from glom import glom

target = {'a': {'b': {'c': 'd'}}}
glom(target, 'a.b.c', default=None)  # returns 'd'

If it's a dictionary you can use get(keyname, value)

{'foo': {'bar': 'baz'}}.get('foo', {}).get('bar')

Combining some of the other answers into a function gives us something that's easily readable and something that can be used with objects and dictionaries.

def optional_chain(root, *keys):
    result = root
    for k in keys:
        if isinstance(result, dict):
            result = result.get(k, None)
        else:
            result = getattr(result, k, None)
        if result is None:
            break
    return result

Using this function you'd just add the keys/attributes after the first argument.

obj = {'a': {'b': {'c': {'d': 1}}}}
print(optional_chain(obj, 'a', 'b'), optional_chain(obj, 'a', 'z'))

Gives us:

{'c': {'d': 1}} None

You can use getattr:

getattr(getattr(foo, 'bar', None), 'baz', None)

Most pythonic way is:

try:
    # do something
    ...
except (NameError, AttributeError) as e:
    # do something else
    ...