欢迎回来！🎉 这节课我们要学习如何处理日期和时间——在实际编程中经常用到的重要技能！
前九节课我们学会了： - 变量和基本数据类型 - 条件判断和循环 - 列表和字典 - 函数（代码的魔法师） - 文件操作（数据持久化） - 模块和包（代码组织） - 面向对象编程（OOP） - 异常和错误处理 - 正则表达式
这节课我们要学习如何处理日期和时间！
import datetime
from datetime import datetime, date, time, timedelta
# 当前日期和时间
now = datetime.now()
print("当前时间:", now)
print("年:", now.year)
print("月:", now.month)
print("日:", now.day)
print("时:", now.hour)
print("分:", now.minute)
print("秒:", now.second)
print("微秒:", now.microsecond)
# 当前日期
today = date.today()
print("\n当前日期:", today)
print("年:", today.year)
print("月:", today.month)
print("日:", today.day)
# 星期几
print("\n星期（0=周一, 6=周日）:", now.weekday())
print("星期（1=周一, 7=周日）:", now.isoweekday())
# 创建指定日期
d = date(2024, 3, 15)
print("指定日期:", d)
# 从时间戳创建
timestamp = 1710451200 # 2024-03-15
d_from_timestamp = date.fromtimestamp(timestamp)
print("从时间戳创建:", d_from_timestamp)
# 从ISO格式字符串创建
d_from_iso = date.fromisoformat("2024-03-15")
print("从ISO字符串创建:", d_from_iso)
# 创建指定时间
t = time(14, 30, 45)
print("指定时间:", t)
print("时:", t.hour)
print("分:", t.minute)
print("秒:", t.second)
print("微秒:", t.microsecond)
# 从ISO格式字符串创建
t_from_iso = time.fromisoformat("14:30:45")
print("从ISO字符串创建:", t_from_iso)
# 创建指定日期时间
dt = datetime(2024, 3, 15, 14, 30, 45)
print("指定日期时间:", dt)
# 合并date和time
d = date(2024, 3, 15)
t = time(14, 30, 45)
dt_combined = datetime.combine(d, t)
print("合并日期和时间:", dt_combined)
# 从时间戳创建
dt_from_timestamp = datetime.fromtimestamp(1710451200)
print("从时间戳创建:", dt_from_timestamp)
# 从ISO格式字符串创建
dt_from_iso = datetime.fromisoformat("2024-03-15T14:30:45")
print("从ISO字符串创建:", dt_from_iso)
now = datetime.now()
# 常用格式
print("默认格式:", now)
print("YYYY-MM-DD:", now.strftime("%Y-%m-%d"))
print("YYYY年MM月DD日:", now.strftime("%Y年%m月%d日"))
print("HH:MM:SS:", now.strftime("%H:%M:%S"))
print("完整格式:", now.strftime("%Y-%m-%d %H:%M:%S"))
print("星期:", now.strftime("%A"))
print("月份:", now.strftime("%B"))
print("12小时制:", now.strftime("%Y-%m-%d %I:%M:%S %p"))
# 格式码说明
"""
%Y 4位年份 (2024)
%y 2位年份 (24)
%m 月份 (01-12)
%B 月份全名 (March)
%b 月份缩写 (Mar)
%d 日期 (01-31)
%A 星期全名 (Friday)
%a 星期缩写 (Fri)
%H 24小时制 (00-23)
%I 12小时制 (01-12)
%M 分钟 (00-59)
%S 秒 (00-59)
%p AM/PM
%f 微秒
%z 时区偏移
"""
# 中文格式化
weekday_names = ["星期一", "星期二", "星期三", "星期四", "星期五", "星期六", "星期日"]
month_names = ["", "一月", "二月", "三月", "四月", "五月", "六月",
"七月", "八月", "九月", "十月", "十一月", "十二月"]
print(f"\n中文格式: {now.year}年{month_names[now.month]}{now.day}日 {weekday_names[now.weekday()]}")
# 解析日期时间字符串
date_str = "2024-03-15 14:30:45"
dt = datetime.strptime(date_str, "%Y-%m-%d %H:%M:%S")
print("解析结果:", dt)
# 不同格式的解析
date_str1 = "2024年03月15日"
dt1 = datetime.strptime(date_str1, "%Y年%m月%d日")
print("解析中文日期:", dt1)
date_str2 = "03/15/2024 2:30 PM"
dt2 = datetime.strptime(date_str2, "%m/%d/%Y %I:%M %p")
print("解析美式日期:", dt2)
# 创建时间差
delta1 = timedelta(days=7)
delta2 = timedelta(weeks=2)
delta3 = timedelta(hours=3, minutes=30)
delta4 = timedelta(days=1, hours=2, minutes=30, seconds=45)
print("7天:", delta1)
print("2周:", delta2)
print("3小时30分:", delta3)
print("混合:", delta4)
# 时间差的属性
print("\ndays:", delta4.days)
print("seconds:", delta4.seconds)
print("total_seconds():", delta4.total_seconds())
now = datetime.now()
print("当前时间:", now)
# 加法
print("\n1天后:", now + timedelta(days=1))
print("1周后:", now + timedelta(weeks=1))
print("3小时后:", now + timedelta(hours=3))
print("30分钟后:", now + timedelta(minutes=30))
# 减法
print("\n1天前:", now - timedelta(days=1))
print("1周前:", now - timedelta(weeks=1))
print("3小时前:", now - timedelta(hours=3))
# 日期相减
d1 = date(2024, 3, 15)
d2 = date(2024, 3, 1)
delta = d1 - d2
print(f"\n{d1} - {d2} = {delta.days}天")
# 时间相减
t1 = datetime(2024, 3, 15, 14, 30)
t2 = datetime(2024, 3, 15, 10, 0)
delta = t1 - t2
print(f"{t1} - {t2} = {delta}")
print(f"总秒数: {delta.total_seconds()}")
def calculate_age(birth_date):
"""计算年龄"""
today = date.today()
age = today.year - birth_date.year
# 如果今年生日还没过，减1岁
if (today.month, today.day) < (birth_date.month, birth_date.day):
age -= 1
return age
# 测试
birth_date = date(2000, 5, 15)
age = calculate_age(birth_date)
print(f"出生日期: {birth_date}")
print(f"年龄: {age}岁")
def is_leap_year(year):
"""判断是否是闰年"""
# 能被4整除但不能被100整除，或者能被400整除
return year % 4 == 0 and (year % 100 != 0 or year % 400 == 0)
# 测试
years = [2000, 2004, 1900, 2023, 2024]
for year in years:
print(f"{year}年是闰年吗？{is_leap_year(year)}")
def days_between(date1, date2):
"""计算两个日期之间的天数"""
delta = date2 - date1
return abs(delta.days)
# 测试
d1 = date(2024, 1, 1)
d2 = date(2024, 12, 31)
print(f"{d1} 到 {d2} 有 {days_between(d1, d2)} 天")
def days_in_month(year, month):
"""获取某个月的天数"""
if month == 12:
next_month = date(year + 1, 1, 1)
else:
next_month = date(year, month + 1, 1)
first_day = date(year, month, 1)
return (next_month - first_day).days
# 测试
print("2024年2月有", days_in_month(2024, 2), "天")
print("2023年2月有", days_in_month(2023, 2), "天")
print("2024年4月有", days_in_month(2024, 4), "天")
def get_week_range(date_obj):
"""获取日期所在周的周一和周日"""
# weekday()返回0=周一, 6=周日
start = date_obj - timedelta(days=date_obj.weekday())
end = start + timedelta(days=6)
return start, end
# 测试
today = date.today()
monday, sunday = get_week_range(today)
print(f"本周: {monday} 到 {sunday}")
import time
# 当前时间戳（秒）
timestamp = time.time()
print("当前时间戳（秒）:", timestamp)
# 时间戳（毫秒）
timestamp_ms = int(time.time() * 1000)
print("当前时间戳（毫秒）:", timestamp_ms)
# 时间戳转datetime
dt = datetime.fromtimestamp(timestamp)
print("时间戳转datetime:", dt)
# datetime转时间戳
dt = datetime.now()
timestamp = dt.timestamp()
print("datetime转时间戳:", timestamp)
import time
print("开始...")
time.sleep(2) # 休眠2秒
print("2秒后...")
time.sleep(0.5) # 休眠0.5秒
print("0.5秒后...")
import time
# 方法1：使用time.time()
start = time.time()
# 执行一些操作
time.sleep(1)
end = time.time()
print(f"耗时: {end - start:.2f}秒")
# 方法2：使用time.perf_counter()（更精确）
start = time.perf_counter()
time.sleep(1)
end = time.perf_counter()
print(f"耗时: {end - start:.2f}秒")
# 方法3：使用装饰器
def timer(func):
def wrapper(*args, **kwargs):
start = time.perf_counter()
result = func(*args, **kwargs)
end = time.perf_counter()
print(f"{func.__name__} 耗时: {end - start:.4f}秒")
return result
return wrapper
@timer
def slow_function():
time.sleep(0.5)
return "完成"
slow_function()
import calendar
# 设置每周的第一天（0=周一, 6=周日）
calendar.setfirstweekday(calendar.MONDAY)
# 打印某个月的日历
print("2024年3月的日历:")
print(calendar.month(2024, 3))
# 打印整年的日历
print("\n2024年的日历:")
print(calendar.calendar(2024))
# 判断是否是闰年
print("\n2024是闰年吗？", calendar.isleap(2024))
print("2023是闰年吗？", calendar.isleap(2023))
# 某个月的第一天是星期几，有多少天
weekday, num_days = calendar.monthrange(2024, 3)
print(f"\n2024年3月: 第一天是星期{weekday}（0=周一），共{num_days}天")
# 某个月的日历矩阵
print("\n2024年3月的日历矩阵:")
print(calendar.monthcalendar(2024, 3))
让我们创建一个实用的日程管理系统！
from datetime import datetime, date, timedelta
import json
from pathlib import Path
class Event:
"""事件类"""
def __init__(self, title, start_time, end_time=None, description=""):
self.title = title
self.start_time = start_time
self.end_time = end_time or start_time + timedelta(hours=1)
self.description = description
self.created_at = datetime.now()
def to_dict(self):
"""转换为字典"""
return {
'title': self.title,
'start_time': self.start_time.isoformat(),
'end_time': self.end_time.isoformat(),
'description': self.description,
'created_at': self.created_at.isoformat()
}
@classmethod
def from_dict(cls, data):
"""从字典创建"""
event = cls(
title=data['title'],
start_time=datetime.fromisoformat(data['start_time']),
end_time=datetime.fromisoformat(data['end_time']),
description=data.get('description', '')
)
event.created_at = datetime.fromisoformat(data['created_at'])
return event
def __str__(self):
return f"📅 {self.start_time.strftime('%Y-%m-%d %H:%M')} - {self.end_time.strftime('%H:%M')} | {self.title}"
class ScheduleManager:
"""日程管理器"""
def __init__(self, data_file="schedule.json"):
self.data_file = Path(data_file)
self.events = []
self.load()
def add_event(self, title, start_time, end_time=None, description=""):
"""添加事件"""
event = Event(title, start_time, end_time, description)
self.events.append(event)
self.save()
print(f"✅ 已添加事件: {title}")
return event
def delete_event(self, index):
"""删除事件"""
if 0 <= index < len(self.events):
event = self.events.pop(index)
self.save()
print(f"✅ 已删除事件: {event.title}")
else:
print("❌ 无效的索引")
def get_events_by_date(self, target_date):
"""获取某一天的事件"""
target_events = []
for event in self.events:
if event.start_time.date() == target_date:
target_events.append(event)
return sorted(target_events, key=lambda e: e.start_time)
def get_upcoming_events(self, days=7):
"""获取未来几天的事件"""
today = date.today()
end_date = today + timedelta(days=days)
upcoming = []
for event in self.events:
event_date = event.start_time.date()
if today <= event_date <= end_date:
upcoming.append(event)
return sorted(upcoming, key=lambda e: e.start_time)
def list_all_events(self):
"""列出所有事件"""
if not self.events:
print("当前没有事件")
return
print("\n" + "="*60)
print(" 📅 所有事件")
print("="*60)
for i, event in enumerate(sorted(self.events, key=lambda e: e.start_time)):
print(f"{i+1}. {event}")
if event.description:
print(f" 描述: {event.description}")
print("="*60 + "\n")
def show_today_schedule(self):
"""显示今天的日程"""
today = date.today()
events = self.get_events_by_date(today)
print(f"\n📅 {today.strftime('%Y年%m月%d日')} 的日程:")
if not events:
print(" 今天没有安排")
else:
for event in events:
print(f" • {event.start_time.strftime('%H:%M')} - {event.title}")
print()
def show_reminders(self):
"""显示提醒（即将发生的事件）"""
now = datetime.now()
one_hour_later = now + timedelta(hours=1)
reminders = []
for event in self.events:
if now <= event.start_time <= one_hour_later:
reminders.append(event)
if reminders:
print("\n🔔 即将开始的事件:")
for event in reminders:
minutes_to_start = int((event.start_time - now).total_seconds() / 60)
print(f" • {event.title} - {minutes_to_start}分钟后开始")
print()
def save(self):
"""保存到文件"""
data = [event.to_dict() for event in self.events]
with open(self.data_file, 'w', encoding='utf-8') as f:
json.dump(data, f, ensure_ascii=False, indent=2)
def load(self):
"""从文件加载"""
if self.data_file.exists():
with open(self.data_file, 'r', encoding='utf-8') as f:
data = json.load(f)
self.events = [Event.from_dict(event_data) for event_data in data]
# 演示日程管理系统
def main():
print("="*60)
print(" 📅 日程管理系统")
print("="*60)
manager = ScheduleManager()
# 添加一些示例事件
now = datetime.now()
manager.add_event(
title="团队会议",
start_time=datetime(now.year, now.month, now.day, 10, 0),
end_time=datetime(now.year, now.month, now.day, 11, 0),
description="讨论项目进度"
)
manager.add_event(
title="午餐",
start_time=datetime(now.year, now.month, now.day, 12, 0),
end_time=datetime(now.year, now.month, now.day, 13, 0)
)
manager.add_event(
title="代码评审",
start_time=datetime(now.year, now.month, now.day, 14, 30),
description="评审新功能代码"
)
# 明天的事件
tomorrow = date.today() + timedelta(days=1)
manager.add_event(
title="客户拜访",
start_time=datetime(tomorrow.year, tomorrow.month, tomorrow.day, 9, 0),
end_time=datetime(tomorrow.year, tomorrow.month, tomorrow.day, 11, 0),
description="拜访重要客户"
)
# 显示今天的日程
manager.show_today_schedule()
# 显示即将开始的事件
manager.show_reminders()
# 显示未来7天的事件
print("\n📆 未来7天的事件:")
upcoming = manager.get_upcoming_events(7)
for event in upcoming:
print(f" • {event}")
# 列出所有事件
manager.list_all_events()
if __name__ == "__main__":
main()
今天我们学会了：
✅ datetime模块：处理日期和时间的核心模块
✅ 创建日期时间对象：date、time、datetime
✅ 格式化：strftime()和strptime()
✅ 时间差计算：timedelta
✅ 常用日期计算：年龄、闰年、天数等
✅ time模块：时间戳、计时、休眠
✅ calendar模块：日历相关操作
✅ 实战项目：日程管理系统
下节课预告：我们会学习网络编程，如何进行HTTP请求和API调用！
继续加油！你已经掌握了Python编程的核心技能！💪