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

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")