Numpy reranging chararray-CodePudding

How can one rerange chararrays without getting a TypeError.

import numpy as np


    bggr =   ([['B', 'G', 'B', 'G'],
               ['G', 'R', 'G', 'R'],
               ['B', 'G', 'B', 'G'],
               ['G', 'R', 'G', 'R']])
    
    
    test = np.chararray((4, 4, 3)) #create empty chararray
    test[:] = ''
    test[::2, ::2, 2]=bggr[0::2, 0::2] #blue
    test[1::2, ::2, 1]=bggr[1::2, 0::2] #green
    test[::2, 1::2, 1]=bggr[0::2, 1::2] #green
    test[1::2, 1::2, 0]=bggr[1::2, 1::2] #red
    print(test)

Traceback (most recent call last):
  File "main.py", line 16, in <module>
    test[::2, ::2, 2]=bggr[0::2, 0::2] #blue
TypeError: list indices must be integers or slices, not tuple

Tried the exact same code with numbers instead of chars and it worked fine. Thank you.

CodePudding user response：

You need to use a numpy array for bggr:

import numpy as np


bggr = np.array([['B', 'G', 'B', 'G'],
                 ['G', 'R', 'G', 'R'],
                 ['B', 'G', 'B', 'G'],
                 ['G', 'R', 'G', 'R']])


test = np.chararray((4, 4, 3)) #create empty chararray
test[::2, ::2, 2]=bggr[0::2, 0::2] #blue
test[1::2, ::2, 1]=bggr[1::2, 0::2] #green
test[::2, 1::2, 1]=bggr[0::2, 1::2] #green
test[1::2, 1::2, 0]=bggr[1::2, 1::2] #red

print(test)

output:

[[['' '' b'B']
  ['' b'G' '']
  ['' '' b'B']
  ['' b'G' '']]

 [['' b'G' '']
  [b'R' b'\x04' '']
  ['' b'G' '']
  [b'R' '' '']]

 [[b'\x06' '' b'B']
  ['' b'G' '']
  ['' '' b'B']
  ['' b'G' '']]

 [['' b'G' '']
  [b'R' '' '']
  ['' b'G' '']
  [b'R' '' '']]]