Python之time时间模块

一、时间格式的转化

1. 时间的转化

import time
s = '2019-7-14'
print(time.strptime(s,'%Y-%m-%d'))
s_time = '09:00:00'
print(time.strptime(s_time,'%H:%M:%S'))

2. 把元组的时间转换为时间戳

import time
tuple_time = time.localtime()
print(tuple_time)
print(time.mktime(tuple_time))

3. 把元组时间转换为字符串时间

import time
tuple_time = time.localtime()
print(time.strftime('%m-%d',tuple_time))
print(time.strftime('%Y-%m-%d',tuple_time))
print(time.strftime('%F',tuple_time))
print(time.strftime('%T',tuple_time))

4. 把时间戳类型转换为字符串时间

import time
import os
pwd_time = os.path.getctime('/etc/passwd')
print('pwd_time',pwd_time)
print(time.ctime(pwd_time))

5. 将时间戳转换为元组

import time
import os
pwd_time = os.path.getctime('/etc/passwd')
print(time.localtime(pwd_time))

6. 元组转换为时间戳

import time
tuple_time = time.localtime()
print(time.mktime(tuple_time))

二、datetime查询时间

1. 当前时间

from datetime import date
from datetime import datetime
print(date.today())
print(datetime.now())

2. 计算几天前的时间

from datetime import date
from datetime import timedelta
d = date.today()
delta = timedelta(days=3)
print(d + delta)    #几天后
print(d - delta)    #几天前

3. 计算几个小时前或后的时间

from datetime import datetime
from datetime import timedelta
now_time = datetime.now()
delta = timedelta(hours=2)
print(now_time)
print(now_time + delta)    #几个小时后
print(now_time - delta)    #几个小时前

4. 计算文件从修改到现在的时间

import os
from datetime import datetime
now_time = datetime.now()
print(now_time)     #当前时间
pwd_time = os.path.getmtime('/etc/passwd')
print(pwd_time)     #文件最后一次修改时间
pwd_time_obj = datetime.fromtimestamp(pwd_time)
print(pwd_time_obj) #转化为时间戳
delta = now_time - pwd_time_obj     #文件从修改到现在的时间
print(delta)

练习：需求如下：

1.获取当前主机信息（操作系统名、主机名、内核版本、硬件架构）

2.获取开机时间和开机时长

3.获取当前登录用户

import os
import psutil
from datetime import datetime

print('主机信息'.center(50,'*'))
info = os.uname()
# print(info)
print(
    """
    操作系统:%s
    主机名称:%s
    内核版本:%s
    硬件架构:%s
    """ %(info.sysname,info.nodename,info.release,info.machine)
)

print('开机信息'.center(50,'*'))
boot_time = psutil.boot_time()  #返回一个时间戳
boot_time_obj = datetime.fromtimestamp(boot_time)
#当前时间
now_time = datetime.now()
delta_time1 = now_time - boot_time_obj

print('开机时间:',boot_time_obj)
print('当前时间:',str(now_time).split('.')[0])
print('开机时长:',str(delta_time1).split('.')[0])

print('当前登录用户'.center(50,'*'))
login_user = psutil.users()[0]
print(login_user.name)