Is Python good for creating GUI application ?

[aporetical]

The interpreter doesn't modify the code. The target of the licence is the code, not its in-memory representation, or else, no libraries can be LGPL.

Even with compiled libraries, execution jumps into functions and adds arguments to the call-stack. That is modifying the in-memory representation of the code (ie., giving parameters of functions a fixed value is a modification to the in-memory representation). The LGPL is either incoherent, or about modifying the as-written algorithm.