Introspection is often seen as a bad coding practice and as such a gadget. Nevertheless, the Python Standard Library provides different tools (among them the ‘inspect’ library) to easily identify a generator, recover the source code of a function or get a function signature. We propose to spend 1/2 hour to dig into what introspection has to offer to developers, to see what tools are available, what you can get out of them and some useful use cases that we met in our practice at Criteo.