replace int column code with text value in Python

import pandas as pd
import numpy as np

da = pd.read_csv("nhanes_2015_2016.csv")
da["DMDEDUC2x"] = da.DMDEDUC2.replace({1: "<9", 2: "9-11", 3: "HS/GED", 4: "Some college/AA", 5: "College",
                                       7: "Refused", 9: "Don't know"})