Inappropriate ioctl for device

I’ve tried running a basic capture per the README.MD instructions under both Python v2.7.9 (with Numpy v1.8.2 & OpenCV v2.4.9.1) and Python 3.4.2 (with Numpy v1.8.2 & OpenCV v3.4.0) and always receive the following errors: Python v2.7.9

Python 2.7.9 (default, Sep 17 2016, 20:26:04)
[GCC 4.9.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from pylepton import Lepton
>>> with Lepton() as l:
...   a,_ = l.capture()
...
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/pylepton/Lepton.py", line 84, in __enter__
    ioctl(self.__handle, SPI_IOC_RD_MODE, struct.pack("=B", Lepton.MODE))
IOError: [Errno 25] Inappropriate ioctl for device

Python v3.4.2

Python 3.4.2 (default, Oct 19 2014, 13:31:11)
[GCC 4.9.1] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from pylepton import Lepton
>>> with Lepton() as l:
...   a,_ = l.capture()
...
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.4/dist-packages/pylepton/Lepton.py", line 84, in __enter__
    ioctl(self.__handle, SPI_IOC_RD_MODE, struct.pack("=B", Lepton.MODE))
OSError: [Errno 25] Inappropriate ioctl for device

Doing a ls /dev reports that my SPI device is spidev0.0.

I’m a complete newbie to Linux and Python and I just have no idea where to even start troubleshooting this, frankly I don’t even know what the error means!

Any help very much appreciated 😃