The solution to this problem is that concatenate your lists to a very large list and then convert that large list into a numpy array.

**Solution:**

First, you have to concatenate the list. For this purpose use np.concatenate, extend the second array to 2D, and then concatenate along axis =1.

`np.concatenate( ( a, b[:,None]) , axis =1)`

**Alternative:**

Alternatively, you can use np.column_stack that take care of it;

`np.column_stack((a , b))`

**Example:**

```
In [84]: a
Out[84]:
array([[54, 30, 55, 12],
[64, 94, 50, 72],
[67, 31, 56, 43],
[26, 58, 35, 14],
[97, 76, 84, 52]])
In [85]: b
Out[85]: array([56, 70, 43, 19, 16])
In [86]: np.concatenate((a,b[:,None]),axis=1)
Out[86]:
array([[54, 30, 55, 12, 56],
[64, 94, 50, 72, 70],
[67, 31, 56, 43, 43],
[26, 58, 35, 14, 19],
[97, 76, 84, 52, 16]])
```

If b is a 1D array of datatype object with shape (1,), then most probably all of the data contained in the only one element in it. If we need to flatten out before concatenating, then we use np.concatenate on it also.

**Here is an example to make it clear.**

```
In [118]: a
Out[118]:
array([[54, 30, 55, 12],
[64, 94, 50, 72],
[67, 31, 56, 43],
[26, 58, 35, 14],
[97, 76, 84, 52]])
In [119]: b
Out[119]: array([array([30, 41, 76, 13, 69])], dtype=object)
In [120]: b.shape
Out[120]: (1,)
In [121]: np.concatenate((a,np.concatenate(b)[:,None]),axis=1)
Out[121]:
array([[54, 30, 55, 12, 30],
[64, 94, 50, 72, 41],
[67, 31, 56, 43, 76],
[26, 58, 35, 14, 13],
[97, 76, 84, 52, 69]])
```