'Camera' object has no attribute '_Camera__dtype'

[zhouht2000]

from pyvcam import pvc
from pyvcam.camera import Camera

pvc.init_pvcam()
cam = next(Camera.detect_camera())
cam.open()
cam.set_roi(2498, 1450, 60, 60)
stack = cam.get_sequence(20) # Getting a sequence of 8 frames

I simply run the basic codes.
Then I get

PS C:\Users\comedia> & C:/Users/comedia/anaconda3/envs/haitao/python.exe "c:/Users/comedia/Desktop/Haitao/python codes/iris 15 camera/camera.py"
Traceback (most recent call last):
File "c:\Users\comedia\Desktop\Haitao\python codes\iris 15 camera\camera.py", line 8, in
stack = cam.get_sequence(20) # Getting a sequence of 8 frames
File "C:\Users\comedia\anaconda3\envs\haitao\Lib\site-packages\pyvcam\camera.py", line 491, in get_sequence
stack = np.empty((num_frames, shape[1], shape[0]), dtype=self.__dtype)
^^^^^^^^^^^^
AttributeError: 'Camera' object has no attribute '_Camera__dtype'. Did you mean: '_Camera__mode'?
PS C:\Users\comedia>

[zhouht2000]

A camera object named cam has already been created

cam.clear_mode = "Never"
cam.exp_mode = "Ext Trig Trig First"
cam.readout_port = 0
cam.speed_table_index = 0
cam.gain = 1

if I run this it gives

PS C:\Users\comedia> & C:/Users/comedia/anaconda3/envs/haitao/python.exe "c:/Users/comedia/Desktop/Haitao/python codes/iris 15 camera/camera.py"
Traceback (most recent call last):
File "C:\Users\comedia\anaconda3\envs\haitao\Lib\site-packages\pyvcam\camera.py", line 41, in getitem
return super(Camera.ReversibleEnumDict, self).getitem(keyOrValue)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^
KeyError: 'Never'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "c:\Users\comedia\Desktop\Haitao\python codes\iris 15 camera\camera.py", line 10, in
cam.clear_mode = "Never"
^^^^^^^^^^^^^^
File "C:\Users\comedia\anaconda3\envs\haitao\Lib\site-packages\pyvcam\camera.py", line 975, in clear_mode
value = self.__clear_modes[keyOrValue] if isinstance(keyOrValue, str) else keyOrValue
~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^
File "C:\Users\comedia\anaconda3\envs\haitao\Lib\site-packages\pyvcam\camera.py", line 45, in getitem
raise ValueError('Invalid key: {0} for {1} - Available keys are: {2}'.format(keyOrValue, self.name, list(self.keys())))
ValueError: Invalid key: Never for clear_modes - Available keys are: ['Auto']
PS C:\Users\comedia>

I guess the codes have some version problems?

[vondrejPM]

Hi, this is rather strange error that we have not seen before. Would it be possible to confirm that you have all the prerequisites installed? What Python version and what IDE do you use?

[zhouht2000]

Hi, this is rather strange error that we have not seen before. Would it be possible to confirm that you have all the prerequisites installed? What Python version and what IDE do you use?

Hi, My python is 3.13.2, IDE is visual studio code. I installed [PVCAM SDK 3.10.1.1] and [PVCAM 3.9.0.4].

First, the Camera class does not define self.__dtype in its init method. Instead, self.__dtype is only initialized inside the start_seq() function. As a result, if you call cam.get_sequence(20) directly—before start_seq()—it will throw an error, since np.empty() is used with self.__dtype, which hasn't been defined yet.
This also explains why the code in seq_mode.py works correctly: it first uses the advanced sequence acquisition, which first calls start_seq() and initializes self.__dtype properly.

Second, the available choices for the two variables you're using do not include "Never" and "Ext Trig Trig First". I'm not sure if you’ve checked that part.

[tomhanak]

The original issue with undefined dtype should be fixed now.

The secondary problem - failing to set clear_mode to 'Never' - is kind of expected behavior.
The camera you use reports it supports only clearing mode 'Auto' as all CMOS cameras and that is what Python interpreter says in the error message.

If you really want to achieve C/C++ behavior, where CLEAR_AUTO is just an alias to CLEAR_NEVER with the same value and both values work, you can use provided constants instead of strings.
I.e. instead of cam.clear_mode = 'Never' use cam.clear_mode = constants.CLEAR_NEVER (don't forget to from pyvcam import constants).