Rainbow Hat python module not working


I was having trouble getting the rainbowhat module to load in Python.
I was getting the following error:

>>> import rainbowhat
Traceback (most recent call last):
  File "", line 1, in 
  File "/usr/lib/python2.7/dist-packages/rainbowhat/__init__.py", line 13, in 
  File "/usr/lib/python2.7/dist-packages/rainbowhat/HT16K33.py", line 52, in begin
    self._device.write_i2c_block_data(self._i2c_addr, HT16K33_SYSTEM_SETUP | HT16K33_OSCILLATOR, [])
IOError: [Errno 5] Input/output error

It turns out this just means the Rainbow Hat is not properly connected.