扩展数据类型练习

# !/usr/bin/env python3
# -*- coding: utf-8 -*-
# @Time : 2020/5/6 23:16
# @Author : "小多肉"
# @Email : 1021181701@qq.com
# @File : exdatatype.py
# @Software: PyCharm


"""
todo:
1、通过列表推导式完成下面数据类型转换
现在有以下数据， li1 = ["{'a':11,'b':2}","[11,22,33,44]"]

需要转换为以下格式： li1 = [{'a':11,'b':2},[11,22,33,44]]
"""

li1 = ["{'a':11,'b':2}","[11,22,33,44]"]
# if 条件判断放在for循环后面
li1 = [eval(i) for i in li1 if isinstance(i,str)]
# 第二种写法，if 条件判断放在for循环前面，此时必须加上else。
li2 = [eval(i) if isinstance(i,str) else i for i in li1 ]
print(li1,"
",li2)


# todo:
"""
2、使用列表推倒式生成一个[0,5,10,15,20,...50]的列表 
"""

li = [i for i in range(51) if i%5 == 0]
print(li)


# todo:
"""
3、使用列表推到式生成一个[page1，page2,page3....page10]的列表
"""

li = ["page{}".format(i) for i in range(1,11)]
print(li)


# todo:
"""
4、 Names=['python','java','php','c','c++','django','unittest','pytest','pymysql'],请通过列表推导式，获取names中字符串长度大于4的元素
    提示 ：列表推导式可以结合三目运算符一起使用
"""

Names=['python','java','php','c','c++','django','unittest','pytest','pymysql']
li4 = [i for i in Names if len(i)>4 ]
print(li4)


# todo:
'''
5、通过列表推导式和字典推导式完成下面数据转换
# 原来数据
str = """
url:www.baidu.com,mobilephone:13760246701,pwd:123456
url:www.baidu.com,mobilephone:15678934551,pwd:234555
url:www.baidu.com,mobilephone:15678934551,pwd:234555
url:www.baidu.com,mobilephone:15678934551,pwd:234555
url:www.baidu.com,mobilephone:15678934551,pwd:234555
"""
# 转换后数据
list = [{'url': 'www.baidu.com', 'mobilephone': '13760246701', 'pwd': '123456'},
        {'url': 'www.baidu.com', 'mobilephone': '15678934551', 'pwd': '234555'},
        {'url': 'www.baidu.com', 'mobilephone': '15678934551', 'pwd': '234555'},
        {'url': 'www.baidu.com', 'mobilephone': '15678934551', 'pwd': '234555'},
        {'url': 'www.baidu.com', 'mobilephone': '15678934551', 'pwd': '234555'}]
'''

string = """
url:www.baidu.com,mobilephone:13760246701,pwd:123456
url:www.baidu.com,mobilephone:15678934551,pwd:234555
url:www.baidu.com,mobilephone:15678934551,pwd:234555
url:www.baidu.com,mobilephone:15678934551,pwd:234555
url:www.baidu.com,mobilephone:15678934551,pwd:234555
"""

exp_str = [{j.split(":")[0]:j.split(":")[1] for j in i.split(",") } for i in string.split("
") if i]
print(exp_str)