Python中的元组,等同于java中的finial对象。一旦定义不能修改。
元组的表现形式
if __name__ == '__main__': tuple1 =() tuple2=(1,) tuple3=(1,2.345,-6,7+8j,"breakloop") tuple4=9,10,22,-1,4-1j tuple5=(tuple1,tuple2,tuple3,tuple4) print("tuple1", tuple1) print("tuple2", tuple2) print("tuple3", tuple3) print("tuple4", tuple4) print("tuple5", tuple5)
相应输出为
tuple1 () tuple2 (1,) tuple3 (1, 2.345, -6, (7+8j), 'breakloop') tuple4 (9, 10, 22, -1, (4-1j)) tuple5 ((), (1,), (1, 2.345, -6, (7+8j), 'breakloop'), (9, 10, 22, -1, (4-1j)))
(1)元组通常使用()来表示。当然也可以不用,例如 tuple4。
(2)若元组中只有一个元素,则该元素后,必须添加“,”,否则将视为基本类型。
(3)元组可以为多种数据类型的组合,跟列表相同。
(4)元组一旦定义,不能修改。
(5)元组可以嵌套,跟列表相同。
访问元组数据
print("tuple1[0]=", tuple1[0]) print("tuple2[0]=", tuple2[0]) print("tuple2[1:3]=",tuple2[1:3]) print("tuple3[1:3]=",tuple3[1:3]) print("tuple3[1:3]=",tuple3[1:7])
相应输出为
IndexError: tuple index out of range tuple2[0]= 1 tuple2[1:3]= () tuple3[1:3]= (2.345, -6) tuple3[1:3]= (2.345, -6, (7+8j), 'breakloop')
(1)若元组为空,则访问元组内任何数据都会报错。
(2)若使用双索引访问,高索引越界,不会报错,返回实际包含的元素。
元组的其它工具方法
print("0 in tuple6 :", 0 in tuple6) #查找 print("4 in tuple6 :", 4 in tuple6) print("min item in tuple6 = ", min(tuple6)) #获取最小值 print("max item in tuple6 = ", max(tuple6)) #获取最大值 print("tumple length =", len(tuple6)) #获取元组长度 print("how many 4 in tuple6 = ",tuple6.count(4)) #获取某一元素的数量 print("the first 4 index = ", tuple6.index(4)) #获取某一元素的第一次出现位置的索引 tuple6=tuple6+tuple2 #连接 print("tuple6+tuple2=", tuple6) tuple6=tuple6*3 #复制 print("tuple6*3=", tuple6)
相应输出为
0 in tuple6 : False 4 in tuple6 : True min item in tuple6 = -5 max item in tuple6 = 187 tumple length = 7 how many 4 in tuple6 = 2 the first 4 index = 1 tuple6+tuple2= (1, 4, 89, 4, 78, 187, -5, 1) tuple6*3= (1, 4, 89, 4, 78, 187, -5, 1, 1, 4, 89, 4, 78, 187, -5, 1, 1, 4, 89, 4, 78, 187, -5, 1)
遍历元素
for a in tuple6: print(a)