Hi there, I have a question concerning numpy.memmap. I'm working with a binary format, consisting of a header of certain size (1024 byte) in the beginning and a 2d-float32 array afterwards. I would like to open the array-part using a memmap-object using mm = n.memmap("test.dat",dtype=n.float32,offset=1024,shape=(2000,32),mode="r+") This works fine. My question is now, if I can in the mean time securely open the file for custom writing by using f = open("test.dat", "r+") or will there be problems? Is there another possibility to do custom writing to the header-part? Thanks, Thorsten