Coding Fun

  In Python, list support + and += operators. They could do the same thing as the method extend(). extend(): iterate through the iterable object and append each element from the iterable to the end of the list to be extended. Its parameter could be any iterable. >>> a = ['a','b','c'] >>> b = ['x','y','z'] >>> a.extend(b) >>> a ['a', 'b', 'c', 'x', 'y', 'z'] + operator: instead of extending the list in place, it creates a new list leaving original list untouched; it is not as effcient as two others.  >>> a = ['a','b','c'] >>> b = ['x','y','z'] >>> c = a + b >>> c ['a', 'b', 'c', 'x', 'y', 'z'] += operator: it extends the list in place which is the same as the extend() method. >>> a = ['a','b','c

  Python lists are mutable, you can add objects to the list in place. Both append() and extend() methods could do the trick. append(): add a single object to the end of the list >>> l = ['a', 'b', 'c'] >>> l.append(['d','e','f']) >>> l ['a', 'b', 'c', ['d', 'e', 'f']] extend(): add all the elements from the iterable to the end of the list >>> l.extend(['d','e','f']) >>> l ['a', 'b', 'c', 'd', 'e', 'f']