Hey there, there's no real equivalent to PHPMyAdmin for web/gui based MySQL management in the Python world, no.
The "Python way" seems to be to let your web framework do this sort of work for you. It depends on what you want to do:
- define new database tables, and and remove columns etc (usually the programmer's job)
- "admin user" or "super user" data entry tasks, eg adding product listings for an online shop
For the former, most web frameworks encourage you to use an ORM, to define your tables as classes, and then the ORM will take care of building tables for you. Django has its own ORM, other frameworks often use the excellent SQLAlchemy
For the latter, Django has its "admin site", which lets super-users log in and manually add or edit data in the application's tables, and it's pretty sweet. I'm not sure what other frameworks may have.
I'd recommend running through the official Django tutorial -- it zips through the ORM and the admin site pretty quickly, you should be up to scratch within a couple of hours...