IIUC you are unzipping a Julia vector of 3-tuples into 3 numpy arrays. You can do this from Python using numpy’s field indexing:
x = ... # Julia array of 3-tuples
x = np.asarray(x) # now it's a numpy.ndarray of 3-tuples
x0 = x["f0"] # numpy.ndarray of the 1st field
x1 = x["f1"] # 2nd field
x2 = x["f2"] # 3rd field
These are all non-copying views into the original x, so should be really fast.