FYI, the formatting of several of the Python code blocks is messed up, starting with lines like this:

```python linenums=”21” def get_value(self, input_key):

Also, might be worth noting that the "The Pythonic Implementation of Python Hash Tables" section seems to cover either Python 3.6 or 3.7, and that the implementation seems to have changed a bit in 3.8: now `sys.getsizeof({}) == 64` and `sys.getsizeof({"a": 100}) == 232`. Does anyone have the low-down on how it's changed and possibly how it's likely to change again in future versions?