[Tutor] Calling class from another class

[Peter Otten]

aishwarya selvaraj wrote:

>  Dear all,
>  I have created 2 classes in 2 separate files.File 1 named atcore_py.pyx
> with class andorCameraSDK3, and file 2 with name  AndorCameraGUI making
> use of TKinter.
> I was able to import  andorCameraSDK3 into  AndorCameraGUI, but I was not
> able to do the other way around, as I need to call the function Plot() in
> file 2 inside function acquireimage() in file 1.
> When I define self.master = master in file 1 and pass this from file 2 as
> self.camera =  andorCameraSDK3(self) , I get an error saying :
> 
>> ​ Exception in Tkinter callback
>>
> 
> Traceback (most recent call last):
>>
> File "/home/ravindra/anaconda2/lib/python2.7/lib-tk/Tkinter.py", line
> 1541,
>> in __call__
>>
> 
> return self.func(*args)
>>
> File "/home/ravindra/PycharmProjects/LiveMode/GUI.py", line 278, in
>> getCameraStringGU
>>
> 
> self.camera = AndorCameraSDK(self)
>>
> File "atcore_py.pyx", line 77, in AndorCameraDriver.
>> andorCameraSDK3.__cinit__
>>
> self.master = master
>>
> AttributeError: 'AndorCameraDriver.andorCameraSDK3' object has no
> attribute
>> 'master'

The attachments didn't make it, but it looks like you are using Cython.

According to

http://cython.readthedocs.io/en/latest/src/userguide/extension_types.html#dynamic-attributes

you cannot add arbitrary attributes to a class written in Cython, you have 
to declare them:

cdef class andorCameraSDK3:
    cdef object master
    ...

> Process finished with exit code 0  ​
>>
>>
> 
> ​
> I'm attaching both the files along with this email. It would be great if
> someone could help me out here. Thanks in advance
> 
> ​
>