A matrix problem. Please help!

[Carl]

I have the following matrix that I want to transform:
    
import random
import Numeric as N
ru = []
for i in range(25):
    ru.append(int(random.uniform(0, 2)))
ru = N.reshape(ru, (5, 5))

>>> ru
array([[1, 0, 1, 1, 1],
       [0, 1, 1, 1, 0],
       [1, 1, 0, 0, 1],
       [0, 1, 0, 0, 1],
       [1, 1, 0, 1, 1]])

Trailing numbers (ie, from left to right) after the first encounter of a "1"
for all rows should equal "0".

Thus, I want this:

>>> ru
array([[1, 0, 0, 0, 0],
       [0, 1, 0, 0, 0],
       [1, 0, 0, 0, 0],
       [0, 1, 0, 0, 0],
       [1, 0, 0, 0, 0]])

Does anyone have a suggestion of a fast and easy way to accomplish the
above?

Carl