You should use a tuple there: it's a collection of fixed size where each slot has an identity. (There's a common confusion in Python circles that the main point of tuples is immutability; that's not so).
Not the parent, but i return heterogeneous lists of the same length to the excel to be used by xlwings. The first row being the headers, but every row below is obviously heterogeneous
"return key, value" is implicit. While "return [key, value]" is explicitly telling the full return-value. And it's (for me) more readable than "return (key, value)".
You should use a tuple there: it's a collection of fixed size where each slot has an identity. (There's a common confusion in Python circles that the main point of tuples is immutability; that's not so).