Op 16-09-13 15:43, Arturo B schreef: > Hello, I'm making Python mini-projects and now I'm making a Latin Square > > (Latin Square: http://en.wikipedia.org/wiki/Latin_square) > > So, I started watching example code and I found this question on > Stackoverflow: > > http://stackoverflow.com/questions/5313900/generating-cyclic-permutations-reduced-latin-squares-in-python > > It uses a list comprenhension to generate the Latin Square, I'm am a newbie > to Python, and I've tried to figure out how this is evaluated: > > a = [1, 2, 3, 4] > n = len(a) > [[a[i - j] for i in range(n)] for j in range(n)] > > I don't understand how the "i" and the "j" changes. > On my way of thought it is evaluated like this: > > [[a[0 - 0] for 0 in range(4)] for 0 in range(4)] > [[a[1 - 1] for 1 in range(4)] for 1 in range(4)] > [[a[2 - 2] for 2 in range(4)] for 2 in range(4)] > [[a[3 - 3] for 3 in range(4)] for 3 in range(4)] > > But I think I'm wrong... So, could you explain me as above? It would help me > a lot. > > Thanks for reading!
Just start your python interpreter and type the following >>> [[(i,j) for i in range(3)] for j in range(3)] That should give you a clue. -- Antoon Pardon -- https://mail.python.org/mailman/listinfo/python-list
