精彩案例
-
输入若干个成绩，求所有成绩的平均值分，每输入一个成绩后询问是否继续输入下一个成绩，回答yes就继续输入下一个成绩，回答no就停止输入成绩
scores = []
while True:
x = input('请输入第{0}个成绩：'.format(len(scores)+1))
try:
scores.append(float(x))
except:
print('非法数据！')
while True:
flag = input('继续输入吗？（yes/no）')
if flag.lower() not in ('yes','no'):
print('只能输入yes或no')
else:
break
if flag == 'no':
break
print('一共输入{0}个成绩，其平均成绩为：{1}'.format(len(scores),sum(scores)/len(scores))) -
编写程序，判断今天是今年的第几天
import time
date = time.localtime()
print(date)
year, month, day = date[:3]
print(year, month, day)
day_month = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
if year % 400 == 0 or (year % 4 == 0 and year % 100 != 0): # 判断是否为闰年
day_month[1] = 29
if month == 1:
print(day)
else:
print(sum(day_month[:month-1]) + day)Python标准库datetime提供了datetime和timedelta对象可以很方便地计算指定年月日时分秒之前或之后的日期时间，还提供了返回结果中包含“今天是今年第几天”"今天是本周第几天"等答案的timetuple()函数，等待
import datetime
from datetime import date
today = datetime.date.today()
print(today)
day = today.timetuple().tm_yday
today = today.replace(year=2018)
print(today)
today = today.replace(month=5)
print(today)
today = today.replace(day=26)
print(today)
now = datetime.datetime.now()
print(now)
now = now.replace(second=39)
print(now)
now = now + datetime.timedelta(days=5)
print(now)
now = now + datetime.timedelta(weeks=-5)
print(now)
# 计算两个日期之间相差多少天
dif = date(year=2019, month=3, day=3) - date(year=2018, month=9, day=23)
print(dif.days)
# 运行结果
2019-03-03
2018-03-03
2018-05-03
2018-05-26
2019-03-03 13:14:20.203989
2019-03-03 13:14:39.203989
2019-03-08 13:14:39.203989
2019-02-01 13:14:39.203989
161标准库calendar也提供了一些与日期操作有关的方法
import calendar
cal = calendar.calendar(2019)
print(cal)
cal_month = calendar.month(2019, 3)
print(cal_month)
# 判断是否为闰年
flag = calendar.isleap(2016)
print(flag)
flag = calendar.isleap(2019)
print(flag)
# 查看指定日期是周几
print(calendar.weekday(2019, 3, 3))
# 执行结果
2019
January February March
Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su
1 2 3 4 5 6 1 2 3 1 2 3
7 8 9 10 11 12 13 4 5 6 7 8 9 10 4 5 6 7 8 9 10
14 15 16 17 18 19 20 11 12 13 14 15 16 17 11 12 13 14 15 16 17
21 22 23 24 25 26 27 18 19 20 21 22 23 24 18 19 20 21 22 23 24
28 29 30 31 25 26 27 28 25 26 27 28 29 30 31
April May June
Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 6 7 1 2 3 4 5 1 2 8 9 10 11 12 13 14 6 7 8 9 10 11 12 3 4 5 6 7 8 915 16 17 18 19 20 21 13 14 15 16 17 18 19 10 11 12 13 14 15 1622 23 24 25 26 27 28 20 21 22 23 24 25 26 17 18 19 20 21 22 2329 30 27 28 29 30 31 24 25 26 27 28 29 30 July August SeptemberMo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 6 7 1 2 3 4 1 8 9 10 11 12 13 14 5 6 7 8 9 10 11 2 3 4 5 6 7 815 16 17 18 19 20 21 12 13 14 15 16 17 18 9 10 11 12 13 14 1522 23 24 25 26 27 28 19 20 21 22 23 24 25 16 17 18 19 20 21 2229 30 31 26 27 28 29 30 31 23 24 25 26 27 28 29 30 October November DecemberMo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su Mo Tu We Th Fr Sa Su 1 2 3 4 5 6 1 2 3 1 7 8 9 10 11 12 13 4 5 6 7 8 9 10 2 3 4 5 6 7 814 15 16 17 18 19 20 11 12 13 14 15 16 17 9 10 11 12 13 14 1521 22 23 24 25 26 27 18 19 20 21 22 23 24 16 17 18 19 20 21 2228 29 30 31 25 26 27 28 29 30 23 24 25 26 27 28 29 30 31 March 2019Mo Tu We Th Fr Sa Su 1 2 3 4 5 6 7 8 9 1011 12 13 14 15 16 1718 19 20 21 22 23 2425 26 27 28 29 30 31TrueFalse6