在Linux和Windows上获得文件创建和修改日期/时间的最佳跨平台方法是什么?
当前回答
以跨平台的方式获取某种修改日期很容易——只需调用os.path.getmtime(path),就会得到文件在path上最后一次修改的Unix时间戳。
另一方面,获取文件创建日期非常繁琐,而且依赖于平台,甚至在三大操作系统之间也有所不同:
On Windows, a file's ctime (documented at https://msdn.microsoft.com/en-us/library/14h5k7ff.aspx) stores its creation date. You can access this in Python through os.path.getctime() or the .st_ctime attribute of the result of a call to os.stat(). This won't work on Unix, where the ctime is the last time that the file's attributes or content were changed. On Mac, as well as some other Unix-based OSes, you can use the .st_birthtime attribute of the result of a call to os.stat(). On Linux, this is currently impossible, at least without writing a C extension for Python. Although some file systems commonly used with Linux do store creation dates (for example, ext4 stores them in st_crtime) , the Linux kernel offers no way of accessing them; in particular, the structs it returns from stat() calls in C, as of the latest kernel version, don't contain any creation date fields. You can also see that the identifier st_crtime doesn't currently feature anywhere in the Python source. At least if you're on ext4, the data is attached to the inodes in the file system, but there's no convenient way of accessing it. The next-best thing on Linux is to access the file's mtime, through either os.path.getmtime() or the .st_mtime attribute of an os.stat() result. This will give you the last time the file's content was modified, which may be adequate for some use cases.
把这些放在一起,跨平台代码应该是这样的……
import os
import platform
def creation_date(path_to_file):
"""
Try to get the date that a file was created, falling back to when it was
last modified if that isn't possible.
See http://stackoverflow.com/a/39501288/1709587 for explanation.
"""
if platform.system() == 'Windows':
return os.path.getctime(path_to_file)
else:
stat = os.stat(path_to_file)
try:
return stat.st_birthtime
except AttributeError:
# We're probably on Linux. No easy way to get creation dates here,
# so we'll settle for when its content was last modified.
return stat.st_mtime
其他回答
有两个方法可以获得mod时间,os.path.getmtime()或os.stat(),但ctime跨平台不可靠(见下文)。
os.path.getmtime()
getmtime(路径) 返回最后一次修改路径的时间。返回值是一个给出 自epoch开始的秒数(请参阅time模块)。提高操作系统。如果文件存在,则错误 不存在或无法访问。1.5.2新版功能。在2.3版更改:如果 os.stat_float_times()返回True,结果是一个浮点数。
os.stat()
stat(path) Perform a stat() system call on the given path. The return value is an object whose attributes correspond to the members of the stat structure, namely: st_mode (protection bits), st_ino (inode number), st_dev (device), st_nlink (number of hard links), st_uid (user ID of owner), st_gid (group ID of owner), st_size (size of file, in bytes), st_atime (time of most recent access), st_mtime (time of most recent content modification), st_ctime (platform dependent; time of most recent metadata change on Unix, or the time of creation on Windows):
>>> import os
>>> statinfo = os.stat('somefile.txt')
>>> statinfo
(33188, 422511L, 769L, 1, 1032, 100, 926L, 1105022698,1105022732, 1105022732)
>>> statinfo.st_size
926L
>>>
在上面的例子中,您将使用statinfo。St_mtime或statinfo。St_ctime分别获取mtime和ctime。
import os, time, datetime
file = "somefile.txt"
print(file)
print("Modified")
print(os.stat(file)[-2])
print(os.stat(file).st_mtime)
print(os.path.getmtime(file))
print()
print("Created")
print(os.stat(file)[-1])
print(os.stat(file).st_ctime)
print(os.path.getctime(file))
print()
modified = os.path.getmtime(file)
print("Date modified: "+time.ctime(modified))
print("Date modified:",datetime.datetime.fromtimestamp(modified))
year,month,day,hour,minute,second=time.localtime(modified)[:-3]
print("Date modified: %02d/%02d/%d %02d:%02d:%02d"%(day,month,year,hour,minute,second))
print()
created = os.path.getctime(file)
print("Date created: "+time.ctime(created))
print("Date created:",datetime.datetime.fromtimestamp(created))
year,month,day,hour,minute,second=time.localtime(created)[:-3]
print("Date created: %02d/%02d/%d %02d:%02d:%02d"%(day,month,year,hour,minute,second))
打印
somefile.txt
Modified
1429613446
1429613446.0
1429613446.0
Created
1517491049
1517491049.28306
1517491049.28306
Date modified: Tue Apr 21 11:50:46 2015
Date modified: 2015-04-21 11:50:46
Date modified: 21/04/2015 11:50:46
Date created: Thu Feb 1 13:17:29 2018
Date created: 2018-02-01 13:17:29.283060
Date created: 01/02/2018 13:17:29
注意:在Linux上文件的ctime与在Windows上略有不同。 Windows用户把他们的时间称为“创建时间”。 Linux用户把他们的时间称为“改变时间”。
在Python 3.4及以上版本中,您可以使用面向对象的pathlib模块接口,其中包括大部分os模块的包装器。下面是一个获取文件统计信息的示例。
>>> import pathlib
>>> fname = pathlib.Path('test.py')
>>> assert fname.exists(), f'No such file: {fname}' # check that the file exists
>>> print(fname.stat())
os.stat_result(st_mode=33206, st_ino=5066549581564298, st_dev=573948050, st_nlink=1, st_uid=0, st_gid=0, st_size=413, st_atime=1523480272, st_mtime=1539787740, st_ctime=1523480272)
有关操作系统的更多信息。Stat_result包含,请参考文档。对于修改时间,你需要fname.stat().st_mtime:
>>> import datetime
>>> mtime = datetime.datetime.fromtimestamp(fname.stat().st_mtime, tz=datetime.timezone.utc)
>>> print(mtime)
datetime.datetime(2018, 10, 17, 10, 49, 0, 249980)
如果你想要Windows上的创建时间,或者Unix上最新的元数据更改,你可以使用fname.stat().st_ctime:
>>> ctime = datetime.datetime.fromtimestamp(fname.stat().st_ctime, tz=datetime.timezone.utc)
>>> print(ctime)
datetime.datetime(2018, 4, 11, 16, 57, 52, 151953)
本文为pathlib模块提供了更多有用的信息和示例。
>>> import os
>>> os.stat('feedparser.py').st_mtime
1136961142.0
>>> os.stat('feedparser.py').st_ctime
1222664012.233
>>>
操作系统。Stat包含了创建时间。os.stat()中包含时间的元素没有st_anything的定义。
所以试试这个:
os.stat('feedparser.py')[8]
将其与ls -lah文件上的创建日期进行比较
它们应该是一样的。