SEQUENCES

- strings, tuples and lists provide many common operation

indexing and slicing:

seq[4]
seq[2:5]
seq[3:]
seq[:4]
seq[-1]  #the last element
seq[-3:] #the last three elements

- lists can be modified (examples):

l[10] = 'test'   #override 10th element
l.append('bla')  #extend the list
del l[4]         #remove 4th element