gistfile1.txt

In [9]: aa=n.random.random((10,15))

In [10]: aa.sum(0)
Out[10]: 
array([ 3.64094547,  5.48642567,  3.86113699,  3.83109877,  4.1542245 ,
        4.43346198,  4.98849284,  4.44047022,  7.10656863,  4.83044752,
        5.07810898,  6.59370274,  7.51975778,  3.9132313 ,  5.2115709 ])

In [11]: aa.sum(1)
Out[11]: 
array([ 8.94158279,  6.35803515,  6.63083928,  7.5355189 ,  7.24503874,
        7.98890149,  9.93868832,  6.52181901,  7.03226278,  6.89695783])