The tool they use to determine py3 support is the following: https://github.com/brettcannon/caniusepython3
They have overridden mysql-python with mysqlclient https://github.com/PyMySQL/mysqlclient-python
They have overridden mysql-python with mysqlclient https://github.com/PyMySQL/mysqlclient-python
I am aware of this, but the fact that the tool is reporting MySQL-python as 3.0 compatible, when it is not, is worrying.