["python","numpy"]
How to copy data from a numpy array to another

What is the fastest way to copy data from array b to array a, without modifying the address of array a. I need this because an external library (PyFFTW) uses a pointer to my array that cannot change. For example: a = numpy.empty(n, dtype=complex) for i in xrange(a.size): a[i] = b[i] It is possible to do it without a loop?
I believe a = numpy.empty_like(b) a[:] = b will copy the values quickly. As Funsi mentions, recent versions of numpy also have the copyto function.