double square(double x){
    return x*x;
}

gcc -c tetr.c -o tetr.o

gcc -shared -Wl,-soname,library.so -o tetr.so tetr.o

import ctypes
lib = ctypes.cdll.LoadLibrary("tetr.so")

ArgumentError: argument 1: <type 'exceptions.TypeError'>: Don't know how to convert parameter 1