a[~(a==0).all(1)]

In [1]: from numpy import *

In [2]: a = array([[4, 1, 1, 2, 0, 4],
                   [3, 4, 3, 1, 4, 4],
                   [1, 4, 3, 1, 0, 0],
                   [0, 4, 4, 0, 4, 3],
                   [0, 0, 0, 0, 0, 0]])

In [3]: print a==0
[[False False False False  True False]
 [False False False False False False]
 [False False False False  True  True]
 [ True False False  True False False]
 [ True  True  True  True  True  True]]

In [6]: print (a==0).all(1)
[False False False False  True]

In [7]: print ~(a==0).all(1)
[ True  True  True  True False]

In [8]: print a[~(a==0).all(1)]
[[4 1 1 2 0 4]
 [3 4 3 1 4 4]
 [1 4 3 1 0 0]
 [0 4 4 0 4 3]]

In [1]: from numpy import *

In [2]: a = matrix([[4, 1, 1, 2, 0, 4],
                    [3, 4, 3, 1, 4, 4],
                    [1, 4, 3, 1, 0, 0],
                    [0, 4, 4, 0, 4, 3],
                    [0, 0, 0, 0, 0, 0]])

In [3]: print a==0
[[False False False False  True False]
 [False False False False False False]
 [False False False False  True  True]
 [ True False False  True False False]
 [ True  True  True  True  True  True]]


In [5]: print (a==0).all(1)
[[False]
 [False]
 [False]
 [False]
 [ True]]

In [6]: print (a==0).all(1).A1
[False False False False  True]

In [7]: print ~(a==0).all(1).A1
[ True  True  True  True False]

In [8]: print a[~(a==0).all(1).A1]
[[4 1 1 2 0 4]
 [3 4 3 1 4 4]
 [1 4 3 1 0 0]
 [0 4 4 0 4 3]]

import numpy as np
m=np.matrix([[1,2,3],[0,0,0], [4,5,6]])
m_nonzero_rows = m[[i for i, x in enumerate(m) if x.any()]]