def _pretty(self, printer, *args):
        m = ((printer._print(self.j1), printer._print(self.m1)),
            (printer._print(self.j2), printer._print(self.m2)),
            (printer._print(self.j3), printer._print(self.m3)))
        hsep = 2
        vsep = 1
        maxw = [-1] * 3
        for j in range(3):
            maxw[j] = max([ m[j][i].width() for i in range(2) ])
        D = None
        for i in range(2):
            D_row = None
            for j in range(3):
                s = m[j][i]
                wdelta = s.width() - maxw[j]
                wleft = wdelta //2
                wright = wdelta - wleft

                s = prettyForm(*s.right(' '*wright))
                s = prettyForm(*s.left(' '*wleft))

                if D_row is None:
                    D_row = s
                    continue
                D_row = prettyForm(*D_row.right(' '*hsep))
                D_row = prettyForm(*D_row.right(s))
            if D is None:
                D = D_row
                continue
            for _ in range(vsep):
                D = prettyForm(*D.below(' '))
            D = prettyForm(*D.below(D_row))
        D = prettyForm(*D.parens())
        return D
dataset/ETHPy150Open sympy/sympy/sympy/physics/quantum/cg.py/Wigner3j._pretty/swapped operands of `-`