When you see a numpy array printed without commas, you just look at its string representation. If you want it to be printed with commas, you can convert it to a Python list:
In [45]: print(arr)
[[12 13 14]
[15 16 17]
[18 19 20]]
In [46]: arr_list = arr.tolist()
In [47]: print(arr_list)
[[12, 13, 14], [15, 16, 17], [18, 19, 20]]
source
share