Raspberry Pi 4: Type object 'str' has no attribute 'fromhex'

[adwinang]

Traceback (most recent call last): File "adwin.py", line 4, in <module> print(my_Var.command_request_knock()) File "/home/pi/Desktop/HuskyLens/HUSKYLENSPython/HUSKYLENS/huskylensPythonLibrary.py", line 178, in command_request_knock cmd = self.cmdToBytes(commandHeaderAndAddress+"002c3c") File "/home/pi/Desktop/HuskyLens/HUSKYLENSPython/HUSKYLENS/huskylensPythonLibrary.py", line 107, in cmdToBytes return bytes.fromhex(cmd) AttributeError: type object 'str' has no attribute 'fromhex'
I encountered this problem when I was running the test.py file.

[adwinang]

ignore the File "adwin.py", copied pasted the wrong error message, but I encountered the same problem for the test.py

[robertprast]

Could you let me know which versions of Python you are using ?

The .fromhex() was added to added to Pythons standard library in versions 3.5. Therefore, please use Python 3.5 or higher.

To check your versions of python you can simply run:
python3 --version or python --version

[adwinang]

Hi, I realised my mistake, I thought I was using python3. But I was using python2

I encountered another problem which is
Traceback (most recent call last): File "test.py", line 28, in <module> print(test.command_request()) File "/home/pi/Desktop/HuskyLens/HUSKYLENS/huskylensPythonLibrary.py", line 187, in command_request self.writeToHuskyLens(cmd) File "/home/pi/Desktop/HuskyLens/HUSKYLENS/huskylensPythonLibrary.py", line 97, in writeToHuskyLens self.huskylensSer.write_i2c_block_data(self.address,12, list(cmd)) OSError: [Errno 121] Remote I/O error
I have used the i2cdetect command to check whether I'm using the correct address, which I was.