python日期

处理时间戳

import datetime

print('Timestamp: {:%Y-%m-%d %H:%M:%S}'.format(datetime.datetime.now()))
print('Timestamp: {:%Y-%b-%d %H:%M:%S}'.format(datetime.datetime.now()))
print('Date now: %s' % datetime.datetime.now())
print('Date today: %s' % datetime.date.today())

today = datetime.date.today()
print("Today's date is {:%b, %d %Y}".format(today))

schedule = '{:%b, %d %Y}'.format(today) + ' - 6 PM to 10 PM Pacific'
schedule2 = '{:%B, %d %Y}'.format(today) + ' - 1 PM to 6 PM Central'
print('Maintenance: %s' % schedule)
print('Maintenance: %s' % schedule2)

输出:

Timestamp: 2014-10-18 21:31:12

Timestamp: 2014-Oct-18 21:31:12

Date now: 2014-10-18 21:31:12.318340

Date today: 2014-10-18

Today's date is Oct, 18 2014

Maintenance: Oct, 18 2014 - 6 PM to 10 PM Pacific

Maintenance: October, 18 2014 - 1 PM to 6 PM Central

我写了一个简单的记录当时执行命令的结果加时间戳记录

cmd = "tsar --check --apache --cpu --mem --load --io --traffic --tcp --partition --nginx --swap"
res = subprocess.check_output(cmd, shell = True).strip().split()
f = open(g_tsar_origin,'w')
f.write("%s %s" % (datetime.now(),res.strip()))
f.close()

unix时间戳和日期转换

使用datetime模块可以转换unix时间

import datetime
print(
    datetime.datetime.fromtimestamp(
        int("1477290239")
    ).strftime('%Y-%m-%d %H:%M:%S')
)

输出显示 2016-10-24 14:23:59

参考 Converting unix timestamp string to readable date in Python

相反，从时间转换成日期转换成unix timestamp方法需要计算，也就是需要计算当前时间到，并且各个python版本的转换方法不同

• Python 2

(datetime.now()-datetime(1970, 1, 1)).total_seconds()

这里datetime格式是 datetime.datetime(2011, 1, 1, 0, 0) (参考 datetime Objects)

import datetime
time1=datetime.datetime(2016,10,24,15,30)
print time1

例如要查 2016-10-22 00:55:26 对应time stamp使用如下方式：

(datetime.datetime(2016,10,22,00,55,26) - datetime.datetime(1970,1,1)).total_seconds()

• Python 3 (< 3.3)

timestamp = (dt - datetime(1970, 1, 1)) / timedelta(seconds=1)

• Python 3.3+

timestamp = dt.replace(tzinfo=timezone.utc).timestamp()

参考 Converting datetime.date to UTC timestamp in Python

文件名修改成带时间戳的后缀

def log_rotate(data):
    rt = time.strftime("%Y%m%d")
    rt_date = ""
    rt_data = data+"."+rt
    # if data file is bigger than 10240000 Byte rename it to rt_data
    if os.path.isfile(data) and os.path.getsize(data) > 10240000 :
        os.rename(data, rt_data)

判断文件大小，超过指定大小进行重命名

获取15分钟或1小时后的时间

datetime支持timedelta函数能够获取指定时间差异的时间

d1 = datetime.datetime.now() + datetime.timedelta(minutes=15)
d2 = datetime.datetime.now() + datetime.timedelta(hours=1)

from datetime import datetime, timedelta
d = datetime.today() - timedelta(days=days_to_subtract)

参考

• In Python, how do I make a datetime that is 15 minutes from now? 1 hour from now? [duplicate]

• How can I subtract a day from a Python date?