windows下用python修改文件创建/访问/写入时间戳 [英] Modify file create / access / write timestamp with python under windows

问题描述

我试图找到一种在windows下使用python修改文件时间戳的简单方法，但是网上没有太多明确的信息.经过一段时间的搜索，我得到了解决方案.为了缩短对其他人的搜索，代码如下.

I tried to find an easy way to modifiy a file timestamp under windows using python, but there was not much clear information on the web. After searching a while I got a solution. To shorten the search for others, the code follows here.

它可能会更简单、更美观，但它确实有效.我唯一没有解决的是夏季时间 - 冬季时间问题，即如果给出夏季时间，结果会相差一小时.也许有人可以添加更正?

It might be done easier and more beautiful, but it works. The only thing I didn't solve is the summer time - winter time issue, i.e. if a time in summer is given, the result differs by one hour. Maybe someone can add a correction?

from win32file import CreateFile, SetFileTime, GetFileTime, CloseHandle 
from win32file import GENERIC_READ, GENERIC_WRITE, OPEN_EXISTING
from pywintypes import Time
import time

import sys
import os

if len(sys.argv)<5:
  pfile = os.path.basename(sys.argv[0])
  print "USAGE:
	%s <createTime> <modifyTime> <accessTime> <FileName>
" % pfile
  print "EXAMPLE:"
  print '%s "01.01.2000 00:00:00" "01.01.2000 00:00:00" "01.01.2000 00:00:00" file' % (pfile) 
  sys.exit()  

# get arguments  
cTime = sys.argv[1] # create
mTime = sys.argv[2] # modify
aTime = sys.argv[3] # access
fName = sys.argv[4]

# specify time format
format = "%d.%m.%Y %H:%M:%S"
offset = 0 # in seconds

# create struct_time object
cTime_t = time.localtime(time.mktime(time.strptime(cTime,format))+offset)
mTime_t = time.localtime(time.mktime(time.strptime(mTime,format))+offset)
aTime_t = time.localtime(time.mktime(time.strptime(aTime,format))+offset)

# visually check if conversion was ok
print
print "FileName: %s" % fName
print "Create  : %s --> %s OK" % (cTime,time.strftime(format,cTime_t))
print "Modify  : %s --> %s OK" % (mTime,time.strftime(format,mTime_t))
print "Access  : %s --> %s OK" % (aTime,time.strftime(format,aTime_t))
print

# change timestamp of file
fh = CreateFile(fName, GENERIC_READ | GENERIC_WRITE, 0, None, OPEN_EXISTING, 0, 0) 
createTime, accessTime, modifyTime = GetFileTime(fh) 
print "Change Create from",createTime,"to %s" % (time.strftime(format,cTime_t))
print "Change Modify from",modifyTime,"to %s" % (time.strftime(format,mTime_t))
print "Change Access from",accessTime,"to %s" % (time.strftime(format,aTime_t))
print

createTime = Time(time.mktime(cTime_t))
accessTime   = Time(time.mktime(aTime_t))
modifyTime    = Time(time.mktime(mTime_t))
SetFileTime(fh, createTime, accessTime, modifyTime) 
CloseHandle(fh)

# check if all was ok
ctime = time.strftime(format,time.localtime(os.path.getctime(fName)))
mtime = time.strftime(format,time.localtime(os.path.getmtime(fName)))
atime = time.strftime(format,time.localtime(os.path.getatime(fName)))

print "CHECK MODIFICATION:"
print "FileName: %s" % fName
print "Create  : %s" % (ctime)
print "Modify  : %s" % (mtime)
print "Access  : %s" % (atime)

推荐答案

您可能需要在两个地方更正冬/夏一小时的差异.在这两种情况下，我们都使用 tm_isdst 字段，time.localtime 可以方便地计算出 夏令时 (DST)对特定时间戳有效.

There are two places where you might want to correct for winter/summer difference of one hour. In both cases, we make use of the tm_isdst field, which time.localtime conveniently calculates to tell us whether Daylight Savings Time (DST) was in effect for a particular timestamp.

如果您在夏季设置冬季时间戳，反之亦然，除非您在调用 SetFileTime 之前进行补偿，否则它将在其匹配季节到来时关闭一个小时:

If you are setting a winter timestamp during summer, or vice versa, it will become off by an hour when its matching season comes around unless you compensate before calling SetFileTime:

now = time.localtime()
createTime = Time(time.mktime(cTime_t) + 3600 * (now.tm_isdst - cTime_t.tm_isdst))
accessTime = Time(time.mktime(aTime_t) + 3600 * (now.tm_isdst - aTime_t.tm_isdst))
modifyTime = Time(time.mktime(mTime_t) + 3600 * (now.tm_isdst - mTime_t.tm_isdst))
SetFileTime(fh, createTime, accessTime, modifyTime) 

输出校正

为了使 Python 报告与 Windows 资源管理器匹配，我们在调用 strftime 之前应用更正:

# check if all was ok
now = time.localtime()
ctime = os.path.getctime(fName)
mtime = os.path.getmtime(fName)
atime = os.path.getatime(fName)
ctime += 3600 * (now.tm_isdst - time.localtime(ctime).tm_isdst)
mtime += 3600 * (now.tm_isdst - time.localtime(mtime).tm_isdst)
atime += 3600 * (now.tm_isdst - time.localtime(atime).tm_isdst)
ctime = time.strftime(format,time.localtime(ctime))
mtime = time.strftime(format,time.localtime(mtime))
atime = time.strftime(format,time.localtime(atime))

两个更正

请注意，如果您同时应用两者，您的 Python 输出将再次与您的输入不匹配.这可能是可取的(见下文)，但如果它困扰您:

Both Corrections

Beware, if you apply both, your Python output will again seem to mismatch your input. This may be desirable (see below), but if it bothers you:

• 如果您更喜欢与一年中的原始时间相同的时间戳，请仅选择 输入更正.
• 仅选择输出校正，如果您习惯于在 DST 生效后一年两次看到它们跳一小时然后消失.

• Choose only Input Correction if you prefer timestamps that look right at their native time of year.
• Choose only Output Correction if you're used to seeing them jump an hour twice a year as DST takes effect and then goes away.

Python 和 Windows 选择了不同的方法在 UTC 和本地时区之间转换时间戳:

Python and Windows have chosen different methods to convert timestamps between UTC and the local time zone:

• Python 使用在时间戳有效的 DST 代码.这样，时间戳全年都有一致的表示.

• Python uses the DST code that was in effect at the timestamp. This way, the time stamp has a consistent representation year-round.

Windows 使用现在生效的 DST 代码.这样，显示的所有时间戳都具有相同的隐式代码.

Windows uses the DST code in effect right now. This way, all time stamps shown have the same implicit code.

如果您使用 '%Z' 在转换后的字符串中包含时区(例如 PST 与 PDT)，这一点很明显，但由于大多数应用程序(包括 Windows 资源管理器)不这样做，明显的一小时不一致可能清单.

This is evident if you use '%Z' to include the time zone in the converted string (PST vs. PDT, for example) but since most apps (including Windows Explorer) do not, an apparent one-hour inconsistency can manifest.

当使用明确的时间码打印时，很明显每列中的标记确实都代表同一时间:

When printed with explicit time codes, it becomes clear that the stamps in each column really do all represent the same instant in time:

File #1 (January)        File #2 (June)
2000-01-30 20:00:00 UTC  2000-06-22 20:00:00 UTC

observed in January in California:
2000-01-30 12:00:00 PST  2000-06-30 13:00:00 PDT  [Python]
2000-01-30 12:00:00 PST  2000-06-30 12:00:00 PST  [Windows]

observed in June in California:
2000-01-30 12:00:00 PST  2000-06-30 13:00:00 PDT  [Python]
2000-01-30 13:00:00 PDT  2000-06-30 13:00:00 PDT  [Windows]

observed in June in New York:
2000-01-30 15:00:00 EST  2000-06-30 16:00:00 EDT  [Python]
2000-01-30 16:00:00 EDT  2000-06-30 16:00:00 EDT  [Windows]

如果我们可以要求 strftime 遵守 tm_isdst 字段，以匹配 Windows 资源管理器和大多数其他显示文件时间戳的应用程序，那就太好了，但至少有一个简单的解决方法可以自己进行计算.

It would be nice if we could ask strftime to honor the tm_isdst field, to match Windows Explorer and most other apps that display file timestamps, but at least there's a simple workaround to do the calculation ourselves.

def adjustForDST (seconds):
    now = time.localtime()
    correction = 60*60 * (now.tm_isdst - time.localtime(seconds).tm_isdst)
    return seconds + correction

time.strftime(format, time.localtime(adjustforDST(mtime)))

来源:

http://bytes.com/topic/python/answers/655606-python-2-5-1-broken-os-stat-modulehttp://search.cpan.org/~shay/Win32-UTCFileTime-1.58/lib/Win32/UTCFileTime.pm

如果 cpan 链接再次因新修订而中断，请按以下方式查找:

If the cpan link breaks again with a new revision, find it this way:

https://www.google.com/search?q=UTCFileTime.pm

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