随手一练

#2.请反转字符串 "aStr"?

print("aStr"[::-1])

#3.输入日期， 判断这一天是这一年的第几天？

import datetime
def dayofday():
    year = input("请输入年份：")
    month = input("请输入月份：")
    day = input("请输入天：")
    date1 = datetime.date(year = int(year), month = int(month), day = int(day))
    date2= datetime.date(year=int(year), month = 1,day = 1)
    return (date1-date2).days + 1

print(dayofday())

#4.打乱一个排好序的list

import random
alist = [1,2,3,4,5]
random.shuffle(alist)
print(alist)

#5.现有字典 d= {'a':24,'g':52,'i':12,'k':33}请按value值进行排序

d= {'a':24,'g':52,'i':12,'k':33}
print(sorted(d.items(),key =lambda x:x[1]))

#6.推导字典

# 方法1：
l = [1,1,2,2,3,4,"a","a","xxxx"]
{v:l.count(v)for v in l if not isinstance(v,(list,dict,set))}

# 方法2：
l = [1,1,2,2,3,4,"a","a","xxxx"]
list({value:None for value in l}.keys())