object有如下子类:
CLASSES object basestring str unicode buffer bytearray classmethod complex dict enumerate file float frozenset int bool list long memoryview property reversed set slice staticmethod super tuple type xrange
序列是Python中最基本的数据结构。序列中的每个元素都分配一个数字 -- 它的位置,或索引,第一个索引是0,第二个索引是1,依此类推。
1、定义
#创建一个列表,只要把逗号分隔的不同的数据项使用方括号括起来即可。如下所示: list1 = ['physics', 'chemistry', 1997, 2000] list2 = [1, 2, 3, 4, 5 ] list3 = ["a", "b", "c", "d"]
2、增
序列内建函数append
L.append(object) -- append object to end
>>>list1=["name","age","address","work"] >>>list1.append("jack") >>>list1 Out[37]: ['name', 'age', 'address', 'work', 'jack'] >>>list1.append(["lucy","jack"]) >>>list1 Out[38]: ['name', 'age', 'address', 'work', 'jack', ['lucy', 'jack']]
L.extend(iterable) -- extend list by appending elements from the iterable
>>>list1=["name","age","address","work"] >>>list1.extend("jack") >>>list1 Out[48]: ['name', 'age', 'address', 'work', 'j', 'a', 'c', 'k'] >>>list1.extend(["jack","lucy"]) >>>list1 >>>Out[50]: ['name', 'age', 'address', 'work', 'j', 'a', 'c', 'k', 'jack', 'lucy'] >>>list1.extend({1:"one",2:"two"}) >>>list1 Out[52]: ['name', 'age', 'address', 'work', 'j', 'a', 'c', 'k', 'jack', 'lucy', 1, 2]
L.insert(index, object) -- insert object before index
>>>list1=["name","age","address","work","name"] >>>list1.insert(0, "work") >>>list1 Out[74]: ['work', 'name', 'age', 'address', 'work', 'name']
3、删
L.pop([index]) -> item -- remove and return item at index (default last).Raises IndexError if list is empty or index is out of range.
L.remove(value) -- remove first occurrence of value.Raises ValueError if the value is not present.
del L ---delete the whole list,so the list doesn't exist.
>>>list1=["name","age","address","work","name"] >>>list1.pop(0) Out[65]: 'name' >>>list1 Out[66]: ['age', 'address', 'work', 'name'] >>>list1.remove("work") >>>list1 Out[68]: ['age', 'address', 'name']
4、改
>>>list1=["name","age","address","work","name"] >>>list1[4]="work" >>>list1 Out[71]: ['name', 'age', 'address', 'work', 'work']
5、查
L.count(value) -> integer -- return number of occurrences of value
>>>list1=["name","age","address","work","name"] >>>list1.count("name") Out[59]: 2
L.index(value, [start, [stop]]) -> integer -- return first index of value.Raises ValueError if the value is not present.
>>>list1=["name","age","address","work","name"] >>>list1.index("name") Out[60]: 0 >>>list1.index("work") Out[61]: 3 >>>list1.index("name",1,len(list1)) Out[63]: 4
列表可以使用下标索引来访问列表中的值
>>>a=[1,2,3,4] >>>a[0] Out[105]: 1 >>>a[-1] Out[106]: 4 >>>a[-3:-1] Out[107]: [2, 3] >>>a[0:2] Out[109]: [1, 2]
6、排序
L.reverse() -- reverse *IN PLACE*
L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*;cmp(x, y) -> -1, 0, 1
>>>list1=['work', 'name', 'age', 'address', 'work', 'name'] >>>list1.reverse() >>>list1 Out[77]: ['name', 'work', 'address', 'age', 'name', 'work'] >>>list1.sort() >>>list1 Out[79]: ['address', 'age', 'name', 'name', 'work', 'work']