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())