元组内置函数用法

元组内置函数用法

元组tuple，我们可以把它看做是 只读列表

• 列表转换为元组： tuple=tuple(list) 例如： list=['Wjz','wjk','wz','hacker','beijing'] tuple=tuple(list) print(tuple) # 输出 ('Wjz','wjk','wz','hacker','beijing')
• 字典转换为元组，元组中元素为字典的key： tuple=tuple(dict) 例如： dic={'wjz':1,'wjk':2} tuple=tuple(dic) print(tuple) # 输出 ('wjz', 'wjk')
• 字符串转换为元组，字符串的每一个字符都为元组的元素： tuple=tuple(str) 例如： str='wjz wjk' tuple=tuple(str) print(tuple) # 输出 ('w', 'j', 'z', ' ', 'w', 'j', 'k')

1.定义：在（）内可以有多个任意类型的值，用逗号分隔元素，用于表示 多个东西

2.作用：类似于列表，不过只能取不能更改

name_list = ['qwesc','zxcsd','mkou','mkou','bdgyh','mkihgg','mkdfia','nmjigf']
my_friend=tuple(name_list)  #把列表转化为元组
print(f'my_friend:{my_friend}')
my_best_friend = ('kang yuan') #默认定义元素为字符串型
my_best_friend_tuple = ('jia','kang','yuan') #定义元素类型为元组
print(f'type(my_best_friend):{type(my_best_friend)}')
print(f'type(my_best_feiend_tuple):{type(my_best_friend_tuple)}')

my_friend:('qwesc', 'zxcsd', 'mkou', 'mkou', 'bdgyh', 'mkihgg', 'mkdfia', 'nmjigf')
type(my_best_friend):<class 'str'>
type(my_best_feiend_tuple):<class 'tuple'>

3.常用操作+内置方法：常用操作和内置方法：

1. 索引取值
2. 切片（顾头不顾尾，步长）
3. 长度len
4. 成员运算in和not in
5. 循环
6. count
7. index

1.索引取值

name_tuple = ('qwesc','zxcsd','mkou','mkou','bdgyh','mkihgg','mkdfia','nmjigf')
name_tuple[3]
print(f"name_tuple[3]:{name_tuple[3]}")

name_tuple[3]:mkou

2.切片 （顾头不顾尾，步长）

name_tuple = ('qwesc','zxcsd','mkou','mkou','bdgyh','mkihgg','mkdfia','nmjigf')
print(f"name_tuple[2:8:2]:{name_tuple[2:8:2]}") #取出索引值2-7，步长为2的元素
print(f'name_tuple[0:5]:{name_tuple[0:5]}') #取出索引值0-4，步长为1的元素
print(f'name_tuple[0:]:{name_tuple[0:]}')  #取出索引值0及之后，步长为1的元素
print(f"name_tuple[:8]:{name_tuple[:8]}")  #取出索引值0-7，步长为1的元素
print(f"name_tuple[:]:{name_tuple[:]}")   #取出所有的步长为1的元素
print(f"name_tuple[::2]:{name_tuple[::2]}")  #取出所有步长为2的元素
print(f"name_tuple[::-1]:{name_tuple[::-1]}")  #取出所有步长为 -1的元素

name_tuple[2:8:2]:('mkou', 'bdgyh', 'mkdfia')
name_tuple[0:5]:('qwesc', 'zxcsd', 'mkou', 'mkou', 'bdgyh')
name_tuple[0:]:('qwesc', 'zxcsd', 'mkou', 'mkou', 'bdgyh', 'mkihgg', 'mkdfia', 'nmjigf')
name_tuple[:8]:('qwesc', 'zxcsd', 'mkou', 'mkou', 'bdgyh', 'mkihgg', 'mkdfia', 'nmjigf')
name_tuple[:]:('qwesc', 'zxcsd', 'mkou', 'mkou', 'bdgyh', 'mkihgg', 'mkdfia', 'nmjigf')
name_tuple[::2]:('qwesc', 'mkou', 'bdgyh', 'mkdfia')
name_tuple[::-1]:('nmjigf', 'mkdfia', 'mkihgg', 'bdgyh', 'mkou', 'mkou', 'zxcsd', 'qwesc')

3.长度len(计算元组中元素总的个数)

name_tuple ,name_tuple2 = ('qwesc','zxcsd','mkou','mkou','bdgyh','mkihgg','mkdfia','nmjigf') ,('mhdsjh','jhhbxnhd')
print(f'first_length:{len(name_tuple)}')
print(f"second_lenght:{len(name_tuple2)}")

first_length:8
second_lenght:2

4.成员计算in 和not in

name_tuple= ('qwesc','zxcsd','mkou','mkou','bdgyh','mkihgg','mkdfia','nmjigf')
print(f"'band' not in name_tuple:{'band' not in name_tuple}")
print(f"'band' in name_tuple:{'band' in name_tuple}")

'band' not in name_tuple:True
'band' in name_tuple:False

5.循环（for循环）

name_tuple = ('qwesc', 'zxcsd', 'mkou', 'mkou', 'bdgyh', 'mkihgg', 'mkdfia', 'nmjigf')
for mottery in range(len(name_tuple)):
    print(mottery,name_tuple[mottery])

0 qwesc
1 zxcsd
2 mkou
3 mkou
4 bdgyh
5 mkihgg
6 mkdfia
7 nmjigf    

6.count（计算元组中相同元素的个数）

name_tuple= ('qwesc','zxcsd','mkou','mkou','bdgyh','mkihgg','mkdfia','nmjigf')
print(f"name_tuple.count('mkou'):{name_tuple.count('mkou')}")  # 获取指定元素的个数

name_tuple.count('mkou'):2

7.index（索引,用于指出元组中某一元素的索引）

name_tuple= ('qwesc','zxcsd','mkou','mkou','bdgyh','mkihgg','mkdfia','nmjigf')
print(f"first:{name_tuple.index('mkou')}")      # 获取指定元素的索引值
print(f"second:{name_tuple.index('bdgyh')}")
print(f"threid:{name_tuple.index('mkdfia')}")

first:2
second:4
threid:6

4.存一个值or多个值：多个值

5.有序or无序：有序（可以按照索引取值）

name_tuple= ('qwesc','zxcsd','mkou','mkou','bdgyh','mkihgg','mkdfia','nmjigf')
print(f"id:{id(name_tuple)}")

id:6439920

6.可变or不可变：无可变与不可变数据类型一说