def perm2tensor(self, g, canon_bp=False):
        """
        Returns a ``TIDS`` instance corresponding to the permutation ``g``

        ``g``  permutation corresponding to the tensor in the representation
        used in canonicalization

        ``canon_bp``   if True, then ``g`` is the permutation
        corresponding to the canonical form of the tensor
        """
        vpos = []
        components = self.components
        pos = 0
        for t in components:
            vpos.append(pos)
            pos += t._rank
        sorted_free = [i[0] for i in self._get_sorted_free_indices_for_canon()]
        nfree = len(sorted_free)
        rank = self._ext_rank
        dum = [[None]*4 for i in range((rank - nfree)//2)]
        free = []
        icomp = -1
        for i in range(rank):
            if i in vpos:
                icomp += vpos.count(i)
                pos0 = i
            ipos = i - pos0
            gi = g[i]
            if gi < nfree:
                ind = sorted_free[gi]
                free.append((ind, ipos, icomp))
            else:
                j = gi - nfree
                idum, cov = divmod(j, 2)
                if cov:
                    dum[idum][1] = ipos
                    dum[idum][3] = icomp
                else:
                    dum[idum][0] = ipos
                    dum[idum][2] = icomp
        dum = [tuple(x) for x in dum]

        return TIDS(components, free, dum)
dataset/ETHPy150Open sympy/sympy/sympy/tensor/tensor.py/TIDS.perm2tensor/original