Python-list and tuple

A list is a built-in data type that is an ordered set of elements that can be added and removed at any time.

classmates = [' Michael ', ' Bob ', ' Tracy '];

1, Len (classmates): Returns the number of list elements 3

2. Index: classmates[0] ' Machael '

Get the last element: Classmates[len-1] or classmates[-1]

The same as the bottom 2nd: classmates[len-2] or classmates[-2]

3. Append element: Append to end Classmates.append (' Adam ')

Insert element at specified location Classmates.insert (1, ' Jack ')

4. Delete element: Delete last element Classmates.pop () returns the value of a pop

Removes the element at the specified location Classmates.pop (1)

5. Replacement element: classmates[1] = ' Sarah '

6. The data type of the elements in the list can be different: L = [' Apple ', 123,true]

7, the elements in the list can also be another list:s = [' Python ', ' Java ', [' asp ', ' php '], ' scheme ']

Len (s) 4 S can be viewed as a two-dimensional array, accessing ' ASP ' s[2][0]

8, if L = [], then Len (L) 0

A tuple tuple is similar to a list, but cannot be modified once the tuple is initialized

Classmates = (' Michael ', ' Bob ', ' Tracy ')

At this time classmates this tuple can not be changed, that is, can not be inserted, deleted, only read, and the same as list.

1, t = (+)

2, T = ()

3, T = (1,)

Python-list and tuple