try: from collections import deque except ImportError: print("SKIP") raise SystemExit # Initial sequence is supported d = deque([1, 2, 3], 10) # iteration over sequence for x in d: print(x) # Iterables larger than maxlen have the beginnings removed, also tests # iteration through conversion to list d = deque([1, 2, 3, 4, 5], 3) print(list(d)) # Empty iterables are also supported deque([], 10) # Extending deques with iterables d.extend([6, 7]) print(list(d)) # Accessing queue elements via index d = deque((0, 1, 2, 3), 5) print(d[0], d[1], d[-1]) # Writing queue elements via index d[3] = 5 print(d[3]) # Accessing indices out of bounds raises IndexError try: d[4] except IndexError: print("IndexError") try: d[4] = 0 except IndexError: print("IndexError")