Python是一种面向对象的语言，但它不像C++一样把标准类都封装到库中，而是进行了进一步的封装，语言本身就集成一些类和函数，比如print，list，dict etc. 给编程带来很大的便捷

Python中列表有点像C中的数组，list里面可以承载不同的数据类型，而且封装了常用的方法用于对list的操作，Python列表索引的下标默认是从第0个开始的，即lia[0].如果需要获取最后一个元素，可以写lia[-1]。

>>> lia = [2]
>>> print lia[0]
2

方法

list.append()

Description

The method append() appends a passed obj into the existing list.

Syntax

list.append(obj)
#obj -- This is the object to be appended in the list.

Return Value

This method does not return any value but updates existing list.

eg

>>> lia.append('A')
>>> lia.append(4)
>>> lia.append([23,5,'12'])
>>> print lia
[2, 'A', 4, [23, 5, '12']]  #将一个集合插入到lia的结尾

list.extend()

Description

The method extend() appends the contents of seq to list.

Syntax

list.extend(seq)
#seq -- This is the list of elements

Return Value

This method does not return any value but add the content to existing list.

eg

>>> lib = ["Another list"]
>>> lia.extend(lib)
>>> print lia
[2, 'A', 4, [23, 5, '12'], 'Another list']

list.insert()

list.insert(index, obj)
#index -- This is the Index where the object obj need to be inserted.
#obj -- This is the Object to be inserted into the given list.

eg

>>> lia.insert(2,'xx')
>>> print lia
[2, 'A', 'xx', 4, [23, 5, '12'], 'Another list']

list.count()

Description

The method count() returns count of how many times obj occurs in list.

Syntax

list.count(obj)
#obj -- This is the object to be counted in the list.

Return Value This method returns count of how many times obj occurs in list.

eg

>>> lia.append('xx')
>>> print lia
[2, 'A', 'xx', 4, [23, 5, '12'], 'Another list', 'xx']
>>> lia.append('xx')
>>> print lia
[2, 'A', 'xx', 4, [23, 5, '12'], 'Another list', 'xx', 'xx']
>>> lia.count('xx')
3

list.remove()

Description This method remove() remove the specified object in list.

Syntax

list.remove(obj)
#obj -- This is the object to be removed from the list.

Return Value

This method does not return any value but removes the given object from the list.

eg

>>> lia.remove('xx')
>>> print lia
[2, 'A', 4, [23, 5, '12'], 'Another list', 'xx', 'xx']
>>> lia.remove('xx')
>>> print lia
[2, 'A', 4, [23, 5, '12'], 'Another list', 'xx']

list.index()

Description The method index() returns the lowest index in list that obj appears.

Syntax

list.index(obj)
#obj -- This is the object to be find out.

Return Value This method returns index of the found object otherwise raise an exception indicating that value does not find.

eg

>>> lia.index('xx')
5

list.pop()

Description

The method pop() removes and returns last object or obj from the list.

Syntax

list.pop(obj=list[-1])
#obj -- This is an optional parameter, index of the object to be removed from the list.

Return Value

This method returns the removed object from the list.

eg

>>> lia.pop()
'xx'
>>> print lia
[2, 'A', 4, [23, 5, '12'], 'Another list']
>>> lia.pop(2)
4
>>> lia.pop(-2)
[23, 5, '12']

list.reverse()

Description

The method reverse() reverses objects of list in place.

Syntax

list.reverse()

Return Value

This method does not return any value but reverse the given object from the list.

eg

>>> lia.reverse()
>>> print lia
['Another list', 'A', 2]

list.sort()

Description

The method sort() sorts objects of list, use compare func if given.

Syntax

list.sort([func])

Return Value

This method does not return any value but reverse the given object from the list.

eg

>>> lia.sort()
>>> print lia
[2, 'A', 'Another list']