Python中實現對Timestamp和Datetime及UTC時間之間的轉換

Python項目中很多時候會需要將時間在Datetime格式和TimeStamp格式之間轉化，又或者你需要將UTC時間轉化為本地時間，本文總結了這幾個時間之間轉化的函數，供大家參考。

一、Datetime轉化為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: # 是否轉化為UTC時間
      dt = dt + datetime.timedelta(hours=-8) # 中國默認時區
    timestamp = total_seconds(dt - EPOCH)
    return long(timestamp)
  return dt
二、TimeStamp轉化為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: # 是否轉化為本地時間
      dt = dt + datetime.timedelta(hours=8) # 中國默認時區
    return dt
  return timestamp
三、當前UTC時間的TimeStamp    
def timestamp_utc_now():
  return datetime2timestamp(datetime.datetime.utcnow())
四、當前本地時間的TimeStamp    
def timestamp_now():
  return datetime2timestamp(datetime.datetime.now())
五、UTC時間轉化為本地時間    
# 需要安裝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")