Collating row entries in 2D array

I have a 2d numpy array (type int64) consisting of 1s and 0s.
I want to club up the 1s and 0s of each row in order to be able to convert them to decimal.

arr = 
[[0  1  0]
[ 0  0  0]
[ 1  1  1]
[ 0  1  1]]

Desired output (each element is dtype str, to make sure leading zeros are not omitted)

[ 010 , 000 , 111 , 011 ]

How can I manipulate the 2d array to get this output? Is it possible in numpy or re packages, by using their functions? Can a for loop be avoided to do this array transformation?

>Solution :

The question is quite unclear, assuming integers in and out, you could use:

a = np.array([[0, 1, 0],
              [0, 0, 0],
              [1, 1, 1],
              [0, 1, 1]])

out = (a[:,::-1]*(10**np.arange(a.shape[1]))).sum(1)

But you won’t have leading zeros…

output:

array([ 10,   0, 111,  11])

Assuming you really want to convert from binary, you should probably use np.packbits:

out = np.packbits(a, axis=1, bitorder='little')

output:

array([[2],
       [0],
       [7],
       [6]], dtype=uint8)

or as flat version:

out = np.packbits(a, axis=1, bitorder='little').ravel()
# array([2, 0, 7, 6], dtype=uint8)