According to the state of Louisiana,
A Louisiana Resident is an individual that is domiciled in the state, maintains a permanent place of abode in the state, or spends more than 6 months of the tax year in the state.
A Nonresident of Louisiana is an individual that did not live in the state at any time during the tax year.
A Part-Year Resident is an individual that moved into or out of the state during the tax year.
If one spouse is a resident and the other is not and a joint federal return was filed, you can file either a resident or nonresident joint return, whichever is more beneficial to you.