day 12 元组的魔法

元祖

元组，其实是对列表的二次加工，元素不可被修改，不能被增加或者删除

li = [11,22,33,44]    # 列表

tu = (111,222,333,444,)  #元祖 


# 元组，其实是对列表的二次加工，元素不可被修改，不能被增加或者删除
# 一般写元组的时候，推荐在最后加一个逗号

1，索引

tu = (111,222,333,444,)
v = tu[0]
# 索引
print(v)

结果：
111

2，切片

tu = (111,222,333,444)
s = tu[0:2]
# 切片
print(s)

结果：
(111, 222)

3，for循环

tu = (111,222,333,444)
for item in tu:
# for循环
    print(item)

结果：

111
222
333
444

 4，count index

获取指定元素在元组中出现的次数

tu = (11,22,33,44)

a = tu.count(22)
b = tu.index(22)
print(a,b)

 

 

######################################### 深灰魔法 #######################################

1,书写格式

1. 书写格式tu = (111,"alex",(11,22),[(33,44)],True,33,44,)一般写元组的时候，推荐在最后加入 元素不可被修改，不能被增加或者删除

 2，索引

tu = (111,"alex",(11,22),[(33,44)],True,33,44,)
v = tu[0]
print(v)

结果：
111

3，切片

tu = (111,"alex",(11,22),[(33,44)],True,33,44,)
v = tu[0:2]
print(v)

结果：
(111, 'alex')

4，可以被for循环，可迭代对象

tu = (111,"alex",(11,22),[(33,44)],True,33,44,)
for item in tu:
    print(item)

结果：

111
alex
(11, 22)
[(33, 44)]
True
33
44

5,转换

 

字符串 转元祖

s = "asdfasdf0"
li = ["asdf","asdfasdf"]
tu = ("asdf","asdf")

v = tuple(s)  
print(v)

结果：
('a', 's', 'd', 'f', 'a', 's', 'd', 'f', '0')

列表转元祖

s = "asdfasdf0"
li = ["asdf","asdfasdf"]
tu = ("asdf","asdf")
v = tuple(li)
print(v)

结果：
('asdf', 'asdfasdf')

元祖转列表

s = "asdfasdf0"
li = ["asdf","asdfasdf"]
tu = ("asdf","asdf")

v = list(tu)
print(v)

结果：
['asdf', 'asdf']

6，join拼接

s = "asdfasdf0"
li = ["asdf","asdfasdf"]
tu = ("asdf","asdf")

v = "_".join(tu)
print(v)

结果：
asdf_asdf

7，extend

li = ["asdf","asdfasdf"]
li.extend((11,22,33,))
print(li)

结果：
['asdf', 'asdfasdf', 11, 22, 33]

8,元组的一级元素不可修改/删除/增加

   元组，有序。

tu = (111,"alex",(11,22),[(33,44)],True,33,44,)
v = tu[3][0][0]
print(v)

结果：
33

tu = (111,"alex",(11,22),[(33,44)],True,33,44,)
v=tu[3]
print(v)

结果：
[(33, 44)]

tu = (111,"alex",(11,22),[(33,44)],True,33,44,)
tu[3][0] = 567
print(tu)

结果：
(111, 'alex', (11, 22), [567], True, 33, 44)

# 6.元组的一级元素不可修改/删除/增加
# tu = (111,"alex",(11,22),[(33,44)],True,33,44,)
# # 元组，有序。