More PyArg questions?

[Arinté]

Is PyArg_ParseTuple and PyArg_ParseTupleKeywords (or whatever it is) the
only two to monkey are with arguments passed from python to c++?

Also, what would be the best way to set a string that the python script
wants to be filled in.  Ex.
some.py
fillinstring = " "
cplusplusapp.read(fillinstring)

What is the best way for C++ apps to fill in that string?  Are python
strings going to be resizable?