why numpy.ndarray is object is not callable in my simple for python loop

I loaded a text file containing a two-column matrix (e.g. below)

[ 
1 3 
2 4 
3 5 
2 0]
My calculation is just to sum each row i.e. 1+3, 2+4, 3+5 and 2+0. I am using the below code:
data=np.loadtxt(fname="textfile.txt")
## to load the above two column 
xy= data for XY in xy: 
i=0 
Z=XY(i,0)+XY(i,1) 
i=i+1 
print (Z)

[ 
1 3 
2 4 
3 5 
2 0]

My calculation is just to sum each row i.e. 1+3, 2+4, 3+5 and 2+0. I am using the below code:

data=np.loadtxt(fname="textfile.txt")
## to load the above two column 
xy= data for XY in xy: 
i=0 
Z=XY(i,0)+XY(i,1) 
i=i+1 
print (Z)

But I received an error saying numpy.ndarray object is not callable. Why does this happen? How can I do this simple calculation? Thanks.