Lists are a very useful construction and one of the basic types in Python. A Python list is an ordered list of objects enclosed by square brackets. You can access the elements of a list using zero-based indexes inside square brackets:
L1 = [5, 6] L1[0] # 5 L1[1] # 6 L1[2] # raises IndexError L2 = ['a', 1, [3, 4]] L2[0] # 'a' L2[2][0] # 3 L2[-1] # last element: [3,4] L2[-2] # second to last: 1
The indexing of the elements starts at zero. You can put objects of any type inside a list, even other lists. Some basic list functions are as follows:
- list(range(n))} creates a list with n elements, starting with zero:
print(list(range(5))) # returns [0, 1, 2, 3, 4]
- len gives the length of a list:
len(['a', 1, 2, 34]) # returns 4
len(['a',[1,2]]) # returns 2
- append is used to append an element to a list:
L = ['a', 'b', 'c']
L[-1] # &apos...
