---ini-enunciat

>>> from robot import posicions_robot

>>> it1 = iter( [('N',30), ('E',20), ('N',10), ('O',15), ('S',60)] ) 
>>> it2 = posicions_robot(it1)
>>> next(it2)
(0, 0)
>>> next(it2)
(0, 30)
>>> for x in it2:
...    print(x, end='/')
(20, 30)/(20, 40)/(5, 40)/(5, -20)/

---fi-enunciat