python如何标准化日期时间格式转化成非标准化格式

from datetime import datetime, timedelta


def humanize_datetime(db_datetime_str):
    # 解析数据库日期时间字符串
    db_datetime = datetime.strptime(db_datetime_str, '%Y-%m-%d %H:%M:%S')

    # 获取当前时间
    now = datetime.now()

    # 计算时间差
    time_diff = now - db_datetime

    # 定义时间单位的阈值
    minute_diff = timedelta(minutes=1)
    hour_diff = timedelta(hours=1)
    day_diff = timedelta(days=1)
    month_diff = timedelta(days=30)  # 假设一个月平均30天
    year_diff = timedelta(days=365)  # 假设一年365天

    # 根据时间差计算描述
    if time_diff < minute_diff:
        return "刚刚"
    elif time_diff < 2 * minute_diff:
        return "1分钟前"
    elif time_diff < hour_diff:
        return f"{time_diff.seconds // 60}分钟前"
    elif time_diff < 2 * hour_diff:
        return "1小时前"
    elif time_diff < day_diff:
        return f"{time_diff.seconds // 3600}小时前"
    elif time_diff < 2 * day_diff:
        return "昨天"
    elif time_diff < month_diff:
        return f"{time_diff.days // 7}周前"
    elif time_diff < 2 * month_diff:
        return "1个月前"
    elif time_diff < year_diff:
        return f"{time_diff.days // 30}个月前"
    elif time_diff < 2 * year_diff:
        return "半年前"
    else:
        return db_datetime.strftime('%Y-%m-%d %H:%M:%S')


# 示例使用
# db_datetime = "2024-03-04 16:30:00"
# print(humanize_datetime(db_datetime))

import time
timeStamp = time.time()
# print(current_time) 
# 输出: 1614846609.368156

import time
struct_time = time.localtime()
# print(struct_time) 
# 输出: time.struct_time(tm_year=2021, tm_mon=3, tm_mday=4, tm_hour=16, tm_min=30, tm_sec=10, tm_wday=3, tm_yday=63, tm_isdst=0)

import datetime
data_time = datetime.datetime.now()
# print(data_time)
# 输出: 2021-03-04 16:30:10.000000

format_time_1 = time.asctime(struct_time)
# print(format_time_1)
# 输出: Thu Mar  4 16:30:10 2021

format_time_2 = time.strftime("%Y-%m-%d %H:%M:%S", struct_time) 
# print(format_time_2)
# 输出: 2021-03-04 16:30:10

%y 两位数的年份表示（00-99）
%Y 四位数的年份表示（000-9999）
%m 月份（01-12）
%d 月内中的一天（0-31）
%H 24小时制小时数（0-23）
%I 12小时制小时数（01-12）
%M 分钟数（00=59）
%S 秒（00-59）

t = "2021-03-04 16:30:10"
#将其转换为时间数组
timeStruct = time.strptime(t, "%Y-%m-%d %H:%M:%S" )
#转换为时间戳:
timeStamp = int (time.mktime(timeStruct))
# print (timeStamp)
# 输出: 1614846610

timeStamp = 1614846610
localTime = time.localtime(timeStamp)
strTime = time.strftime( "%Y-%m-%d %H:%M:%S" , localTime)
print (strTime)
# 输出: 2021-03-04 16:30:10

import time
import datetime
#先获得时间数组格式的日期
threeDayAgo = (datetime.datetime.now() - datetime.timedelta(days=3))
#转换为时间戳:
timeStamp = int(time.mktime(threeDayAgo.timetuple()))
#转换为其他字符串格式:
strTime = threeDayAgo.strftime( "%Y-%m-%d %H:%M:%S" )
# print (strTime)
# 输出: 2021-03-01 16:30:10