How to read or write the a s h r i file attributes on Windows using Python and ctypes?

Question

For the records:

• a means \'archivable\'
• s means \'system\'
• h means \'hidden\'
• r mean

Answer 1

With the help of eriksuns comments to my question i solved it. Here is the code from my question but now using ctypes, stat and os.scandir. It requires Python 3.5+. Writes are ~50 times faster and reads are ~900 times faster.

Python code:

from ctypes import WinDLL, WinError, get_last_error
from stat import \
    FILE_ATTRIBUTE_ARCHIVE as A, FILE_ATTRIBUTE_SYSTEM as S, \
    FILE_ATTRIBUTE_HIDDEN as H, FILE_ATTRIBUTE_READONLY as R, \
    FILE_ATTRIBUTE_NOT_CONTENT_INDEXED as I
from os import scandir, stat

def example_usage():
    path = 'C:\\test\\'
    # https://docs.python.org/3/library/ctypes.html#ctypes.WinDLL
    kernel32 = WinDLL('kernel32', use_last_error=True)

    print('\njust read the ashri attributes:')
    # https://docs.python.org/3/library/os.html#os.DirEntry
    for entry in scandir(path):
        a,s,h,r,i = myattrib(kernel32, entry)
        print(entry.path, a,s,h,r,i)

    print("\nset the readonly attribute on each entry:")
    for entry in scandir(path):
        a,s,h,r,i = myattrib(kernel32, entry, r=True)
        print(entry.path, a,s,h,r,i)

    print("\nset attributes more than once on the same entry:")
    for entry in scandir(path):
        a,s,h,r,i = myattrib(kernel32, entry, a=False, s=False, h=False, r=False, i=False)
        print(entry.path, a,s,h,r,i)
        a,s,h,r,i = myattrib(kernel32, entry, update=True, a=True, s=True, h=True, r=True, i=True)
        print(entry.path, a,s,h,r,i)

# Use update=True when you call this function a second time on the same DirEntry object.
def myattrib(kernel32, entry, update=False, a=None, s=None, h=None, r=None, i=None):

    # get the file attributes as an integer.
    if not update: # faster
        attrs = entry.stat(follow_symlinks=False).st_file_attributes
    else: # slower but reflects changes
        # notice that this will raise a WinError Access denied on some entries,
        # for example C:\System Volume Information\
        attrs = stat(entry.path, follow_symlinks=False).st_file_attributes

    # construct the new attributes
    newattrs = attrs
    def set(attr, value):
        nonlocal newattrs
        # use '{0:032b}'.format(number) to understand what this does.
        if value is True: newattrs = newattrs | attr
        elif value is False: newattrs = newattrs & ~attr
    set(A, a)
    set(S, s)
    set(H, h)
    set(R, r)
    set(I, i if i is None else not i)
    # optional add more attributes here, see
    # https://docs.python.org/3/library/stat.html#stat.FILE_ATTRIBUTE_ARCHIVE

    # write the new attributes if they changed
    if newattrs != attrs:
        if not kernel32.SetFileAttributesW(entry.path, newattrs):
            raise WinError(get_last_error())

    # return an info tuple
    return (
        bool(newattrs & A),
        bool(newattrs & S),
        bool(newattrs & H),
        bool(newattrs & R),
        not bool(newattrs & I)
    )

if __name__ == '__main__':
    example_usage()

Output:

just read the ashri attributes:
C:\test\hidden.txt True False True False True
C:\test\normal.txt True False False False True
C:\test\readonly.txt True False False True True
C:\test\systemfile.txt True True False False True

set the readonly attribute on each entry:
C:\test\hidden.txt True False True True True
C:\test\normal.txt True False False True True
C:\test\readonly.txt True False False True True
C:\test\systemfile.txt True True False True True

set attributes more than once on the same entry:
C:\test\hidden.txt False False False False False
C:\test\hidden.txt True True True True True
C:\test\normal.txt False False False False False
C:\test\normal.txt True True True True True
C:\test\readonly.txt False False False False False
C:\test\readonly.txt True True True True True
C:\test\systemfile.txt False False False False False
C:\test\systemfile.txt True True True True True