Meaning of ST_INO (os.stat() output) in Windows OS - windows

Question

Can anyone tell me what the meaning of the value for st_ino is when running os.stat() on Windows (Python 3.5.3)?
In earlier Python releases, this contained dummy values, but this has recently changed and I couldn't find how it is calculated/generated. I suspect that it differs based on the file system (NTFS, FAT, ...)
Example
import os
stat = os.stat(r'C:\temp\dummy.pdf')
for attr in dir(stat):
if attr.startswith('st_'):
print('{}: {}'.format(attr,
stat.__getattribute__(attr)))
Result
st_atime: 1495113452.7421005
st_atime_ns: 1495113452742100400
st_ctime: 1495113452.7421005
st_ctime_ns: 1495113452742100400
st_dev: 2387022088
st_file_attributes: 33
st_gid: 0
st_ino: 10414574138828642
st_mode: 33060
st_mtime: 1494487966.9528062
st_mtime_ns: 1494487966952806300
st_nlink: 1
st_size: 34538
st_uid: 0
Background
I used the shutil.copyfile() function an ran into an SameFileError. After looking through the code (and despite what it says in the comments of shutil.py) the shutil._samefile() function does not compare pathnames in Windows. Instead, it uses os.path.samefile() which compares the st_ino and st_dev values.
Both source and target file resided on the same device (volume), which would explain why the value for st_dev was the identical. But I'm still puzzled as to why st_ino had the same value for both files.
Remark: both files were on a Sharepoint volume mounted using webDAV, so their st_ino value may have been 0 (dummy), which would explain why they were equal. I'm still curious though ;-)
Update
As I suspected, the value for st_ino returned for the files residing on the Sharepoint volume (WebDAV), was 0, as was the value for st_dev. This is the reason for (incorrect) SameFileError. Example output:
\\sharepoint#SSL\AUT.pdf os.stat_result(st_mode=33206, st_ino=0, st_dev=0, st_nlink=1, st_uid=0, st_gid=0, st_size=4717, st_atime=1495031011, st_mtime=1495031011, st_ctime=1495031570)
\\sharepoint#SSL\ING.pdf os.stat_result(st_mode=33206, st_ino=0, st_dev=0, st_nlink=1, st_uid=0, st_gid=0, st_size=4722, st_atime=1495031203, st_mtime=1495031203, st_ctime=1495031733)
\\sharepoint#SSL\WAG.pdf os.stat_result(st_mode=33206, st_ino=0, st_dev=0, st_nlink=1, st_uid=0, st_gid=0, st_size=4710, st_atime=1495031511, st_mtime=1495031511, st_ctime=1495031912)