test_rootdataset.py 文件源码

def create_simple_tree(nevents):
    """Create a simple TTree with a couple of branches."""
    t = TTree('aTTree','A TTree')
    t.Branch('run', AddressOf(pytree, 'run'),'run/I')
    t.Branch('evt', AddressOf(pytree, 'evt'),'evt/I')
    t.Branch('x', AddressOf(pytree, 'x'),'x/F')
    t.Branch('y', AddressOf(pytree, 'y'),'y/F')
    t.Branch('z', AddressOf(pytree, 'z'),'z/F')
    for i in range(nevents):
        pytree.run = 1 if (i<500) else 2
        pytree.evt = i
        pytree.x = gauss(0., 10.)
        pytree.y = gauss(0, 10.)
        pytree.z = gauss(5., 50.)
        t.Fill()
    return t