How to get file creation & modification date/times in Python?
Getting some sort of modification date in a cross-platform way is easy - just call os.path.getmtime(path)
and you'll get the Unix timestamp of when the file at path
was last modified.
Getting file creation dates, on the other hand, is fiddly and platform-dependent, differing even between the three big OSes:
- 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 throughos.path.getctime()
or the.st_ctime
attribute of the result of a call toos.stat()
. This won't work on Unix, where thectime
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 toos.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 inst_crtime
) , the Linux kernel offers no way of accessing them; in particular, the structs it returns fromstat()
calls in C, as of the latest kernel version, don't contain any creation date fields. You can also see that the identifierst_crtime
doesn't currently feature anywhere in the Python source. At least if you're onext4
, 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 eitheros.path.getmtime()
or the.st_mtime
attribute of anos.stat()
result. This will give you the last time the file's content was modified, which may be adequate for some use cases.
Putting this all together, cross-platform code should look something like this...
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
You have a couple of choices. For one, you can use the os.path.getmtime
and os.path.getctime
functions:
import os.path, time
print("last modified: %s" % time.ctime(os.path.getmtime(file)))
print("created: %s" % time.ctime(os.path.getctime(file)))
Your other option is to use os.stat
:
import os, time
(mode, ino, dev, nlink, uid, gid, size, atime, mtime, ctime) = os.stat(file)
print("last modified: %s" % time.ctime(mtime))
Note: ctime()
does not refer to creation time on *nix systems, but rather the last time the inode data changed. (thanks to kojiro for making that fact more clear in the comments by providing a link to an interesting blog post)
The best function to use for this is os.path.getmtime(). Internally, this just uses os.stat(filename).st_mtime
.
The datetime module is the best manipulating timestamps, so you can get the modification date as a datetime
object like this:
import os
import datetime
def modification_date(filename):
t = os.path.getmtime(filename)
return datetime.datetime.fromtimestamp(t)
Usage example:
>>> d = modification_date('/var/log/syslog')
>>> print d
2009-10-06 10:50:01
>>> print repr(d)
datetime.datetime(2009, 10, 6, 10, 50, 1)