python datetime时间格式的相互转换问题

# 时间的替换
import time,datetime
today = datetime.datetime.today()
print(\'当前时间：\',today)
print(\'当前时间转换成整h整m整s:\',today.replace(minute=0, second=0))
# 时间的加减
res1 = today + datetime.timedelta(days=1,minutes=60)
print(\'增加的时间为res:\',res1)

res0 = datetime.datetime.now()
print(\'未格式化时间res0：\',res0)
# 将时间转字符串格式化
res2 = datetime.datetime.now().strftime(\"%Y/%m/%d\")
print(\'格式化后的时间res:\',res2)
# 字符串转时间
res3 = datetime.datetime.strptime(\'2018/10/11\', \"%Y/%m/%d\")
print(\'字符串转特定的时间res：\',res3)

 # 转成时间元组
print(\'转成时间元组:\',today.timetuple())

#日期0000时间格式转换为普通时间格式
str_time =\'2018-12-14 00:00:00\'
start_date = datetime.datetime.strptime(str_time, \"%Y-%m-%d %H:%M:%S\")
print(\'start_date:\',start_date)

print(\'---------第二部分----------\')

from datetime import datetime
from datetime import timedelta
# 1) 获取当前日期和时间
today = datetime.today()  # 返回当前时间时分秒都为0
print(\'当前today:\',today)
today1 = datetime.now() # 返回当前日期和时间
# now.hour # 时
# now.minute # 分
# now.isoweekday（）# 返回的1-7代表周一--周日；
# now.weekday（）# 返回的0-6代表周一--到周日
# 而标准格式种%w 1-6表示周一--周六，0代表周日
print(\'today1\', today1 )
today2 = datetime.utcnow() # 返回当前东八区时间就是比当时时间少8个小时
print(\'today2:\',today2)


# 2) 获取指定日期和时间,加减计算
time= datetime(2019, 5, 12, 12, 13, 14)
d= time + timedelta(weeks=0, days=0, hours=0, minutes=0, seconds=0, milliseconds=0, microseconds=0, )
#依次为 \"周\" \"天\", \"时\",\"分\",\"秒\",\"毫秒\",\"微秒\"
print(\'time:\',time)
print(\'d:\',d)

time1= \"2019-5-12 12:13:14\"		# 字符串 日期
d1 = datetime.strptime(str(time1),\'%Y-%m-%d %H:%M:%S\')
plus= d1 + timedelta(days=1)		# 加
minus = d1 - timedelta(days=1)		# 减
print(\'d1:\',d1)
print(\'plus:\',plus)
print(\'minus:\',minus)

time2= 20190512121314
d2 = datetime.strptime(str(time2),\'%Y%m%d%H%M%S\')
delta = d2 + timedelta(days=1)
print(\'time2:\',time2)
print(\'d2:\',d2 )
print(\'delta:\',delta)

# 3) 日期datetime-timestamp 时间戳相互转
now_stamp = time.timestamp()
print(\'指定时间对应时间戳 :\', now_stamp)

print(\'对应本地时间 :\', datetime.fromtimestamp(now_stamp ))
print(\'UTC标准时间 :\', datetime.utcfromtimestamp(now_stamp ))
print(\'本周的第几天:\', datetime.fromtimestamp(now_stamp ).weekday())


# 4) datetime 时间 转换为str字符串
now = datetime.now()
print(\'当前时间的的:\', now)
print(\'转换为str字符串:\',now.strftime(\'%Y%m%d%H%M%S\'))

print(\'--------第三部分-------------\')
import datetime
from datetime import timedelta

now = datetime.datetime.now()
print(\'now:\',now)
# 今天
today = now
print(\'today:\',today)
# 昨天
yesterday = now - timedelta(days=1)
print(\'yesterday:\',yesterday)
# 明天
tomorrow = now + timedelta(days=1)
print(\'tomorrow:\',tomorrow)
# 当前季度
now_quarter = now.month / 3 if now.month % 3 == 0 else now.month / 3 + 1
print(\'now_quarter:\',now_quarter)
# 本周第一天和最后一天
this_week_start = now - timedelta(days=now.weekday())
this_week_end = now + timedelta(days=6 - now.weekday())
print(\'this_week_start:\',this_week_start)
print(\'this_week_end:\',this_week_end)
# 上周第一天和最后一天
last_week_start = now - timedelta(days=now.weekday() + 7)
last_week_end = now - timedelta(days=now.weekday() + 1)
print(\'last_week_start:\',last_week_start)
print(\'last_week_end:\',last_week_end)

# 本月第一天和最后一天
this_month_start = datetime.datetime(now.year, now.month, 1)
month = now.month + 1
if month == 13:
  month = 1
  year = now.year + 1
  this_month_end = datetime.datetime(now.year + 1, 1, 1) - timedelta(days=1)
  print(\'this_month_end:\',this_month_end )
else:
  this_month_end = datetime.datetime(now.year, now.month + 1, 1) - timedelta(days=1)
  print(\'this_month_end:\',this_month_end )
# 上月第一天和最后一天
last_month_end = this_month_start - timedelta(days=1)
last_month_start = datetime.datetime(last_month_end.year, last_month_end.month, 1)
print(\'last_month_end:\',last_month_end)
print(\'last_month_start:\',last_month_start)
# 本季第一天和最后一天
month = (now.month - 1) - (now.month - 1) % 3 + 1
this_quarter_start = datetime.datetime(now.year, month, 1)
this_quarter_end = datetime.datetime(now.year, month + 3, 1) - timedelta(days=1)
print(\'this_quarter_start:\',this_quarter_start)
print(\'this_quarter_end:\',this_quarter_end)
# 上季第一天和最后一天
last_quarter_end = this_quarter_start - timedelta(days=1)
last_quarter_start = datetime.datetime(last_quarter_end.year, last_quarter_end.month - 2, 1)
print(\'last_quarter_end:\',last_quarter_end)
print(\'last_quarter_start:\',last_quarter_start)

# 本年第一天和最后一天
this_year_start = datetime.datetime(now.year, 1, 1)
this_year_end = datetime.datetime(now.year + 1, 1, 1) - timedelta(days=1)
print(\'this_year_start:\',this_year_start)
print(\'this_year_end:\',this_year_end)
# 去年第一天和最后一天
last_year_end = this_year_start - timedelta(days=1)
last_year_start = datetime.datetime(last_year_end.year, 1, 1)
print(\'last_year_end:\',last_year_end)
print(\'last_year_start:\',last_year_start)