Python's equivalent to null-conditional operator introduced in C# 6

Question

Is there an equivalent in Python to C# null-conditional operator?

System.Text.StringBuilder sb = null;
string s = sb?.ToString(); // No error

Answer 1

I wrote this function with your required behavior. An advantage of this over chaining and is that it's easier to write when it comes to long chains. Heads up this doesn't work with object keys, only attributes.

def null_conditional(start, *chain):
    current = start
    for c in chain:
        current = getattr(current, c, None)
        if current is None:
            break
    return current

Here's some tests I ran so you can see how it works

class A(object):
    b = None
    def __init__(self, v):
        self.b = v

class B(object):
    c = None
    def __init__(self, v):
        self.c = v    

a_1 = A(B(2))
a_2 = A(None)
print(null_conditional(a_1, 'b', 'c')) # 2
print(null_conditional(a_1, 'b', 'd')) # None
print(null_conditional(a_2, 'b', 'c')) # None
print(null_conditional(None, 'b')) # None
print(null_conditional(None, None)) # TypeError: attribute name must be string