Python开发——数据类型【元祖】

元祖的定义

 tu = (11,22,33,44,)
 print(tu)       # (11, 22, 33, 44)

 tu = tuple((11,22,33,44,))
 print(tu)       # (11, 22, 33, 44)

元祖的特性

 # 可存放多个值
 # 不可变【一级元素不可修改】
 # 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
 # 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

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

切片

 # 切片
 I = ("egon","alex","seven","yuan")
 print(I[1:3])           # ('alex', 'seven')
 print(I[1:])            # ('alex', 'seven', 'yuan')
 print(I[:3])            # ('egon', 'alex', 'seven')
 print(I[1:-1])          # ('alex', 'seven')
 print(I[:])             # ('egon', 'alex', 'seven', 'yuan')
 print(I[::3])           # ('egon', 'yuan')  跨度为3
 print(I[::-1])          # ('yuan', 'seven', 'alex', 'egon')     反转了

长度

 # 长度
 I = ("egon","alex","seven","yuan")
 print(len(I))           #

包含

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

循环

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

拼接

 I = ("egon","alex","seven","yuan")
 s = "_".join(I)
 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