python ternary operator with assignment

Question

I am new to python. I\'m trying to write this

if x not in d:
    d[x] = {}
q = d[x]

in a more compact way using the ternary operator

Answer 1

That's what setdefault() is for:

q = d.setdefault(x, {})

It does exactly what you want:

• Return d[x] if x is a key in d
• Assign {} to d[x] if x is not yet a key and return that