字典推导式 enumerate zip

字典推导式
# 一.enumerate
"""
enumerate(iterable,[start=0])
功能:枚举 ; 将索引号和iterable中的值,一个一个拿出来配对组成元组,通过迭代器返回
参数:
iterable: 可迭代性数据 (常用:迭代器,容器类型数据,可迭代对象range)
start: 可以选择开始的索引号(默认从0开始索引)
返回值:迭代器
"""

# 基本语法
from collections import Iterator,Iterable
lst =["王文","吕洞宾","何仙姑","铁拐李","张国老","曹国舅","蓝采和","韩湘子"]
it = enumerate(lst)
it = enumerate(lst,start=100)
print(isinstance(it,Iterator))

# next
print( next(it) )

# for + next (推荐,数据较大时使用)
for i in range(3):
print(next(it))

# for
for i in it:
print(i)

# list 强转迭代器
print(list(it))

# (1) 字典推导式 配合 enumerate 来实现
dic = {k:v for k,v in enumerate(lst,start=100)}
print(dic)
"""
(100, '王文')
(101, '吕洞宾')
(102, '何仙姑')
(103, '铁拐李')
(104, '张国老')
(105, '曹国舅')
(106, '蓝采和')
(107, '韩湘子')
"""

# (2) 使用dict强转迭代器,瞬间得到字典
dic = dict( enumerate(lst,start=100) )
print(dic)

### 二.zip
"""
特点:按照索引配对
zip(iterable, ... ...)
功能: 将多个iterable中的值,一个一个拿出来配对组成元组,通过迭代器返回
iterable: 可迭代性数据 (常用:迭代器,容器类型数据,可迭代对象range)
返回: 迭代器
"""
# 基本语法
# lst1 = ["孙华","王飞","朝志"]
# lst2 = ["健宁","韩晓","朝气"]
# lst3 = ["刘文博","历史园","张旭"]

# 在索引下标同时存在时,才会进行配对,否则舍弃.
lst1 = ["开启","王飞","于志"]
lst2 = ["健明","韩晓"]
lst3 = ["刘文博"]

it = zip(lst1,lst2,lst3)
print(list(it))

# (1) 字典推导式 配合 zip 来实现
lst_key = ["ww","axd","yyt"]
lst_val = ["王维","安东","杨涛"]

# ('ww', '王维'), ('axd', '安东'), ('yyt', '杨涛')
dic = {k:v for k,v in zip(lst_key , lst_val) }
print(dic)

# (2) 使用dict强转迭代器,瞬间得到字典
dic = dict( zip(lst_key , lst_val) )
print(dic)