On Nov 9, 4:47 pm, Ognjen Bezanov <ogn...@mailshack.com> wrote: > Hello all, > > Say I have a python variable: > > a = "hello" > > Is it possible for me to get the physical address of that variable (i.e. > where it is in RAM)? > > I know that id(a) will give me it's memory address, but the address > given does not seem to correlate with the physical memory. Is this even > possible?
I'm going to guess that A. You don't really want physical address but logical address (i.e., the address where you might access the memory with a C pointer), and B. You want the address not of the object itself, but of the data within (that is, you'd want the "pointer" you receive to point to the ASCII string hello) Python's way to handle cases like this is called buffer protocol, but it only operates at the C-extension level. There is a set of functions in the C API that look like this PyObject_AsReadBuffer(obj,**buffer,*len) Calling this will return the address of the string "hello" in *buffer. See C API Reference Manual for more details. This function can also be called from ctypes, but I don't remember the exact procedure for modifying input arguments through a pointer. Note: If you really want a PHYSCIAL RAM address you'll have to make some OS-specific system call (I think) with the logical address, probably needing superuser privileges. Obviously this call isn't exposed in Python, because there's no use for it in Python. Unless you're programming DMA transfers or something like that, there's no use for it in C, either. Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
