str,list,tuple 都是序列,序列即是有序的
序列的共同操作:
1、通过序号访问数据
>>> 'hello world'[0] 'h' >>> [1,2,3,4,'abc'][2] 3 >>> (2,3,'python',4)[2] 'python'
2、切片操作
>>> [1,2,3,4,'abc','python'][-3:-1] [4, 'abc'] >>> 'hello world'[0:2] 'he' >>> (1,2,3,4,'abc','python')[-3:-1] (4, 'abc')
3、+ 、 * 操作
>>> 'hello' + 'world' 'helloworld' >>> 'hello world'*3 'hello worldhello worldhello world'
4、in, not in 操作
>>> 'h' in 'hello world' True >>> 'python' in [1,2,3,4,'abc','python'] True >>> 'python' not in [1,2,3,4,'abc','python'] False
5、len() ,max() , min() 操作
>>> len('hello world') 11 >>> len([1,2,3,4,'abc','python']) 6 >>> len((1,3,4,'abc','python')) 5 >>> max('hello world') 'w' >>> min('hello world') ' ' >>> max([1,2,3,4,'abc','python']) Traceback (most recent call last): File "<pyshell#5>", line 1, in <module> max([1,2,3,4,'abc','python']) TypeError: '>' not supported between instances of 'str' and 'int' >>> min([1,2,3,4]) 1 >>> max((1,2,3,4)) 4
查询’w‘的ascii的位置
>>> ord('w') 119 >>> ord(' ') 32 >>> ord(1) Traceback (most recent call last): File "<pyshell#14>", line 1, in <module> ord(1) TypeError: ord() expected string of length 1, but int found