Reading and writing an odù — notation

An odù is written as eight marks in two columns of four. A mark is either single (one stroke, I) or double (two strokes, II). This file records the pattern as an eight-character string in which 1 means a single line and 2 means a double line, the first four characters are the right-hand leg and the last four the left-hand leg, and each group of four is read top to bottom. So Ọ̀gbẹ̀ is 11111111 (four single marks doubled), Ọ̀yẹ̀kú is 22222222, Ìwòrì is 21122112, and the àmúlù Ọ̀gbẹ̀-Ọ̀yẹ̀kú is 11112222. The 0/1 notation that circulates in the scholarly literature maps onto this file's notation by 1 to 0 and 2 to 1, since a single mark is conventionally 0 there and a double mark 1; the same Ọ̀gbẹ̀ is 00000000 and the same Ọ̀yẹ̀kú is 11111111 in that scheme, which is why the two conventions must never be mixed without saying which is in use.