Braid to DT

The conversion from braid to DT

def dt_code(self):
        r"""
        Returns the dt_code

        INPUT:
            - Either a braidword, gauss_code, dt_code

        OUTPUT:
            - DT Code representation of the INPUT

        EXAMPLES::
        """
        if self._dt_code != None:
            return self._dt_code

        elif self._braid != None:
            b = list(self._braid.Tietze())
            N = len(b)
            #b1 = [abs(x) for x in b]
            #b1 = max(b1)
            label = [0 for i in range(2*N)]
            string = 1
            next_label = 1
            type1 = 0
            crossing = 0
            while(next_label <= 2*N):
                string_found = 0
                for i in range(crossing, N):
                    if(abs(b[i]) == string or abs(b[i]) == string - 1):
                        string_found = 1
                        crossing = i
                        break
                if(string_found == 0):
                    for i in range(0,crossing):
                        if(abs(b[i]) == string or abs(b[i]) == string - 1):
                            string_found = 1
                            crossing = i
                            break
                if(label[2*crossing + next_label%2] == 1):
                    return "error"
                else:
                    label[2*crossing + next_label%2] =  next_label
                    next_label = next_label + 1
                if(type1 == 0):
                    if(b[crossing] < 0):
                        type1 = 1
                    else:
                        type1 = -1
                else:
                    type1 = -1 * type1
                    if((abs(b[crossing]) == string and b[crossing] * type1 > 0) or (abs(b[crossing]) != string and b[crossing] * type1 < 0)):
                        if(next_label%2 == 1):
                            label[2*crossing] = label[2*crossing] * -1
                if(abs(b[crossing]) == string):
                    string = string + 1
                else:
                    string = string - 1                    
                crossing = crossing + 1
                
            code = [0 for i in range(N)]
            for i in range(N):
                for j in range(N):
                    if label[2*j+1] == 2*i+1:
                        code[i] = label[2*j]
                        break
            return code
                
        elif self._gauss_code != None:
            return "Not Implemented Error"