in the python:
Code
my_array = [1000.0111000, 2000.0022000, 3000.0003000]
n=0
for x in my_array:
    print ("{:.9f}".format(x),)
    n+=x
print ("{:.9f}".format(n),)


is output:
1000.011100000
2000.002200000
3000.000300000
6000.013600000