Python中实现对Timestamp和Datetime及UTC时间之间的转换

http://www.jb51.net/article/63654.htm 

Python项目中很多时候会需要将时间在Datetime格式和TimeStamp格式之间转化，又或者你需要将UTC时间转化为本地时间，本文总结了这几个时间之间转化的函数，供大家参考。
一、Datetime转化为TimeStamp


def datetime2timestamp(dt, convert_to_utc=False):
  ''' Converts a datetime object to UNIX timestamp in milliseconds. '''
  if isinstance(dt, datetime.datetime):
    if convert_to_utc: # 是否转化为UTC时间
      dt = dt + datetime.timedelta(hours=-8) # 中国默认时区
    timestamp = total_seconds(dt - EPOCH)
    return long(timestamp)
  return dt
二、TimeStamp转化为Datetime


def timestamp2datetime(timestamp, convert_to_local=False):
  ''' Converts UNIX timestamp to a datetime object. '''
  if isinstance(timestamp, (int, long, float)):
    dt = datetime.datetime.utcfromtimestamp(timestamp)
    if convert_to_local: # 是否转化为本地时间
      dt = dt + datetime.timedelta(hours=8) # 中国默认时区
    return dt
  return timestamp
三、当前UTC时间的TimeStamp


def timestamp_utc_now():
  return datetime2timestamp(datetime.datetime.utcnow())
四、当前本地时间的TimeStamp


def timestamp_now():
  return datetime2timestamp(datetime.datetime.now())
五、UTC时间转化为本地时间


# 需要安装python-dateutil
# Ubuntu下：sudo apt-get install python-dateutil
# 或者使用PIP：sudo pip install python-dateutil
from dateutil import tz
from dateutil.tz import tzlocal
from datetime import datetime
  
# get local time zone name
print datetime.now(tzlocal()).tzname()
  
# UTC Zone
from_zone = tz.gettz('UTC')
# China Zone
to_zone = tz.gettz('CST')
  
utc = datetime.utcnow()
  
# Tell the datetime object that it's in UTC time zone
utc = utc.replace(tzinfo=from_zone)
  
# Convert time zone
local = utc.astimezone(to_zone)
print datetime.strftime(local, "%Y-%m-%d %H:%M:%S")