The class to control the TSL2561 to work with python 2. It works with Raspberry pi 3. Sensor module using the TSL2561 seems there are a variety of implementation. This class is moving by mounting of strawberry Linux company.
python-smbus is needed.
$ sudo apt-get install python-smbus
There is one problem. At High gain and high illumination, Raw data isn't sometimes right. (raw data will be 5047 fixing)
When it's useful to you, I'm happy.