The column showed in the pictures below had missing values and I was trying to replace them with the median. I don’t know if it worked or not but it keeps on displaying <bound method NDFrame._add_numeric_operations I have no idea what this means and it can’t be good since it was suppose to show the median values in the place of missing values.
median is a method, not an attribute.
You need to call it with
df["LiteracyRate"] = df["LiteracyRate"].replace(np.NaN, df["LiteracyRate"].median())