元祖的定义

1 tu = (11,22,33,44,)
2 print(tu)       # (11, 22, 33, 44)
3 
4 tu = tuple((11,22,33,44,))
5 print(tu)       # (11, 22, 33, 44)

元祖的特性

1 # 可存放多个值
2 # 不可变【一级元素不可修改】
3 # 按照从左到右的顺序定义元祖,下标从0开始顺序访问,有序
4 # 元祖【一级元素】不可以进行增加、删除、修改操作

元祖的常用操作

索引

1 # 索引
2 I = ("egon","alex","seven","yuan")
3 print(I[0])             # egon
4 print(I[-1])            # yuan
5 print(I[-2])            # seven

切片

1 # 切片
2 I = ("egon","alex","seven","yuan")
3 print(I[1:3])           # ('alex', 'seven')
4 print(I[1:])            # ('alex', 'seven', 'yuan')
5 print(I[:3])            # ('egon', 'alex', 'seven')
6 print(I[1:-1])          # ('alex', 'seven')
7 print(I[:])             # ('egon', 'alex', 'seven', 'yuan')
8 print(I[::3])           # ('egon', 'yuan')  跨度为3
9 print(I[::-1])          # ('yuan', 'seven', 'alex', 'egon')     反转了

长度

1 # 长度
2 I = ("egon","alex","seven","yuan")
3 print(len(I))           # 4

包含

1 # 包含
2 I = ("egon","alex","seven","yuan")
3 if "yuan" in I:
4     print("ok")     # ok

循环

1 # 循环
2 I = ("egon","alex","seven","yuan")
3 for i in I:
4     print(i)

拼接

1 I = ("egon","alex","seven","yuan")
2 s = "_".join(I)
3 print(s)        # egon_alex_seven_yuan

注:元祖、列表中的元素,全部为字符串时可以用join拼接为字符串,否则只能使用for循环拼接

  字符串只能通过索引去取值、不能修改

 

posted on 2018-03-14 17:58  &&||!  阅读(138)  评论(0编辑  收藏  举报