cirq.PAULI_BASIS

cirq.PAULI_BASIS = {'I': array([[1., 0.], [0., 1.]]), 'X': array([[0., 1.], [1., 0.]]), 'Y': array([[ 0.+0.j, -0.-1.j], [ 0.+1.j, 0.+0.j]]), 'Z': array([[ 1., 0.], [ 0., -1.]])}

The four Pauli matrices (including identity) keyed by character.