Index error, delete row from array if column has a value

问题

I have a array 'x' with four columns.

For each row if the 4th column has a value of 1 then I want to delete that entire row:

x = np.array([[1,2,3,0],[11,2,3,24],[1,22,3,1],[1,22,3,1], [5,6,7,8], [9,10,11,1]])
for i in range(0,len(x)):
    if x[i][4]==0:
        x=np.delete(x, i,0)

I get the following error:

Traceback (most recent call last):
File "", line 2, in
if x[i][4]==0:
IndexError: index out of bounds

回答1:

You can use indexing:

>>> x[x[:,3] != 1]
array([[ 1,  2,  3,  0],
       [11,  2,  3, 24],
       [ 5,  6,  7,  8]])

回答2:

You're trying to reference the fourth column with [4], but since it's zero based it's actually [3]

回答3:

The index of a list starts from 0. So, since there are 4 elements, the indexes are :0,1,2,3. So, if you have to check the 4th element, use index 3.

if x[i][3]==0:
     pass

This will work

来源：https://stackoverflow.com/questions/18858396/index-error-delete-row-from-array-if-column-has-a-value