python学习——练习题(4)

"""
题目:输入某年某月某日,判断这一天是这一年的第几天?
"""
import datetime
import time
from functools import reduce


def calculate1(t):
    """
    直接利用python的datetime模块计算
    :param t:
    :return:
    """
    print("计算一", end=":")
    print(t.strftime("%j"))


def calculate2(t):
    """
    自己手动计算一下
    :param t:
    :return:
    """
    print("计算二", end=":")
    days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
    daysLeap = [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
    year = t.year
    if year % 400 == 0 or (year % 4 == 0 and year % 100 != 0):
        print(sum(daysLeap[:t.month - 1]) + t.day)
    else:
        print(sum(days[:t.month - 1]) + t.day)


def calculate3(t):
    """
    高手简化后的calculate2
    :param t:
    :return:
    """
    print("计算三", end=":")
    days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
    year = t.year
    if year % 400 == 0 or (year % 4 == 0 and year % 100 != 0):
        days[1] = 29
    print(sum(days[0: t.month - 1]) + t.day)


def calculate4(t):
    """
    利用字典来计算
    :param t:
    :return:
    """
    print("计算四", end=":")
    dayDict = {0: 0, 1: 31, 2: 59, 3: 90, 4: 120, 5: 151, 6: 181, 7: 212, 8: 243, 9: 273, 10: 304, 11: 334, 12: 365}
    year = t.year
    d = dayDict[t.month - 1] + t.day
    if year % 400 == 0 or (year % 4 == 0 and year % 100 != 0):
        d += 1
    print(d)


def calculate5(t):
    """
    利用time模块来计算,注意和datetime模块进行区分
    :param t:
    :return:
    """
    print("计算五", end=":")
    t = time.strptime(t.strftime("%Y-%m-%d"), "%Y-%m-%d")
    print(t[7])


def calculate6(t):
    """
    利用datetime的时间相减来计算
    :param t:
    :return:
    """
    print("计算六", end=":")
    t1 = datetime.date(t.year, 1, 1)
    t2 = t - t1
    print(t2.days + 1)


def calculate7(t):
    """
    利用time的时间相减来计算,注意与datetime进行区分,它不能直接减,需要转成时间戳才能减
    以为时间戳是以1970年为基点计算的,所以该方法只能计算1970以后(不包括1970)的时间
    :param t:
    :return:
    """
    print("计算七", end=":")
    t1 = time.strptime(t.strftime("%Y-01-01"), "%Y-%m-%d")
    t1 = time.mktime(t1)
    t = time.strptime(t.strftime("%Y-%m-%d"), "%Y-%m-%d")
    t = time.mktime(t)
    t2 = t - t1
    t2 = t2 // (3600 * 24)
    print(int(t2) + 1)


def calculate8(t):
    """
    利用reduce函数来计算,中间有用到三元运算符
    在Python 3里,reduce()函数已经被从全局名字空间里移除了,它现在被放置在fucntools模块里
    用的话要 先引入 from functools import reduce
    :param t:
    :return:
    """
    print("计算八", end=":")
    year = t.year
    days = [0, 31, 28 if year % 4 else 29 if year % 100 else 28 if year % 400 else 29, 31, 30, 31, 30, 31, 31, 30, 31,
            30, 31]
    print(reduce(lambda a, b: a + b, days[0: t.month]) + t.day)


def calculate9(t):
    """
    利用位运算来计算闰年:
    分析 year&3 等价于 year%4:因为二进制转十进制是:2**0+2**1+2**2+。。。,可见2**2之后的都可以被4整除
    同理 year&15 等价 year%16
    根据闰年计算规则我们可以知道:不能被4整除的年份肯定不是闰年,而能被4整除又能被25整数但不能再被16整数的也不是闰年,其余全是闰年
    可得 year%4 or year%16 and !year%25  这些都不是闰年,反之!(year%4 or year%16 and !year%25)为闰年
    转为位运算!(year&3 or year&15  and !(year%25))
    :param t:
    :return:
    """
    print("计算九", end=":")
    days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
    year = t.year
    if not(year & 3 or year & 15 and not(year % 25)):
        days[1] = 29
    print(sum(days[0: t.month - 1]) + t.day)


def answer():
    """
    通过try来判断输入的日期是否正确
    :return:
    """

    year = input("输入年:")
    if year == "q":
        return
    month = input("输入月:")
    day = input("输入日:")
    try:
        t = datetime.date(int(year), int(month), int(day))
        calculate1(t)
        calculate2(t)
        calculate3(t)
        calculate4(t)
        calculate5(t)
        calculate6(t)
        calculate7(t)
        calculate8(t)
        calculate9(t)
    except ValueError:
        print("输入的日期错误")
    print("继续,或输入q推出")
    answer()


answer()

  

posted @ 2017-12-07 19:16  longphui  Views(195)  Comments(0Edit  收藏  举报