[174]python获取特殊时间

python计算程序运行时间

方法1

import datetime

starttime = datetime.datetime.now()

#long running

endtime = datetime.datetime.now()

print (endtime - starttime).seconds

方法 2

start = time.time()

run_fun()

end = time.time()

print end-start

方法3

start = time.clock()

run_fun()

end = time.clock()

print end-start

方法1和方法2都包含了其他程序使用CPU的时间，是程序开始到程序结束的运行时间。

方法3算只计算了程序运行的CPU时间

time和datetime

Python中有两个模块可以完成时间操作：time和datetime，相比较而言datetime更强大

以下分别是两个模块的具体信息

>>> dir(time)
['__doc__', '__name__', '__package__', 'accept2dyear', 'altzone', 'asctime', 'clock', 'ctime', 'daylight', 'gmtime', 
'localtime', 'mktime', 'sleep', 'strftime', 'strptime', 'struct_time', 'time', 'timezone', 'tzname', 'tzset']
>>> dir(datetime.datetime)
['__add__', '__class__', '__delattr__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', 
'__hash__', '__init__', '__le__', '__lt__', '__ne__', '__new__', '__radd__', '__reduce__', '__reduce_ex__', '__repr__',
 '__rsub__', '__setattr__', '__sizeof__', '__str__', '__sub__', '__subclasshook__', 'astimezone', 'combine', 'ctime', 
'date', 'day', 'dst', 'fromordinal', 'fromtimestamp', 'hour', 'isocalendar', 'isoformat', 'isoweekday', 'max', 'microsecond',
 'min', 'minute', 'month', 'now', 'replace', 'resolution', 'second', 'strftime', 'strptime', 'time', 'timetuple', 'timetz', 'today', 
'toordinal', 'tzinfo', 'tzname', 'utcfromtimestamp', 'utcnow', 'utcoffset', 'utctimetuple', 'weekday', 'year']

如果要获取微秒级别的时间差，可以利用以下代码

import datetime

begin = datetime.datetime.now()
end = datetime.datetime.now()
k = end - begin

print (end-begin).days # 0 天数
print (end-begin).total_seconds() # 30.029522 精确秒数
print (end-begin).seconds # 30 秒数
print (end-begin).microseconds # 29522 毫秒数

再看下k的属性和方法

>>> dir(k)
['__abs__', '__add__', '__class__', '__delattr__', '__div__', '__doc__', '__eq__', '__floordiv__', '__format__', '__ge__', 
'__getattribute__', '__gt__', '__hash__', '__init__', '__le__', '__lt__', '__mul__', '__ne__', '__neg__', '__new__', '__nonzero__',
 '__pos__', '__radd__', '__rdiv__', '__reduce__', '__reduce_ex__', '__repr__', '__rfloordiv__', '__rmul__', '__rsub__', '__setattr__',
 '__sizeof__', '__str__', '__sub__', '__subclasshook__', 'days', 'max', 'microseconds', 'min', 'resolution', 'seconds', 'total_seconds']

k为datetime.timedelta类型，以上是timedelta的所有的属性和函数
利用以下代码可以获取以秒为单位的时间差，小数点后6位为微秒。

k.total_seconds()

>>> k.total_seconds()
2303.277522

Python 获取本周、上周、下周周一、周天的日期

1、获取本周(指定日期)周一、周天的日期

# date: "2022-08-09"
def get_current_week(date=None):
    if date:
        duty_date = datetime.datetime.strptime(str(date), '%Y-%m-%d')
        monday, sunday = duty_date, duty_date
    else:
        monday, sunday = datetime.date.today(), datetime.date.today()
    one_day = datetime.timedelta(days=1)
    while monday.weekday() != 0:
        monday -= one_day
    while sunday.weekday() != 6:
        sunday += one_day
 
    # return monday, sunday
    # 返回时间字符串
    return datetime.datetime.strftime(monday, "%Y-%m-%d"), datetime.datetime.strftime(sunday, "%Y-%m-%d")

2、获取上周周一、周天的日期

# date: "2022-08-09"
def get_last_week(date=None):
    if date:
        today = datetime.datetime.strptime(str(date), '%Y-%m-%d')
    else:
        today = datetime.datetime.today()
    end_time = today - datetime.timedelta(days=today.isoweekday())
    start_time = end_time - datetime.timedelta(days=6)
    return start_time.strftime("%Y-%m-%d"), end_time.strftime("%Y-%m-%d")

3、获取下周周一、周天的日期

# date: "2022-08-09"
def get_next_week(date=None):
    if date:
        today = datetime.datetime.strptime(str(date), '%Y-%m-%d')
    else:
        today = datetime.datetime.today()
    start_time = today + datetime.timedelta(days=7-today.weekday())
    end_time = start_time + datetime.timedelta(days=6)
    return start_time.strftime("%Y-%m-%d"), end_time.strftime("%Y-%m-%d")

4、根据开始日期、结束日期返回这段时间里所有天的集合

def get_dates(start_date, end_date):
    dates = list()
    start_date = datetime.datetime.strptime(start_date, '%Y-%m-%d')
    end_date = datetime.datetime.strptime(end_date, '%Y-%m-%d')
    dates.append(start_date.strftime('%Y-%m-%d'))
    while start_date < end_date:
        start_date += datetime.timedelta(days=1)
        dates.append(start_date.strftime('%Y-%m-%d'))
    return dates

参考：https://blog.youkuaiyun.com/rantengfei1986/article/details/128008001