How to use IFileOperation from ctypes

Question

I want to use IFileOperation to copy files from python code -

• It's fast(er than python)
• You get a nice dialog
• Doesn't block Python

On Windows 10, Python 3.8 -

import ctypes

ctypes.windll.shell32.IFileOperation

doesn't seem to exist.

How can I reach IFileOperation (Not the deprecated SHFileOperation API) using ctypes?

Answer 1

This question put me on track, as it shows that COM loading Windows functionality is in fact avialable from ctypes, albeit it requires a bit more work.

The question uses comtypes.GUID as the only (non standard) dependency.

Looking at comtypes itself, it's pure python and uses ctypes (for CoCreateInstance and all else), and the paths to the windows functions needed to load and handle the COM object can be found, specifically -

import ctypes
ctypes.oledll.ole32.CoCreateInstance()

The CLSIDs need to be put explicitly, as in the referred question -

IID_IFileOperation  = '{947AAB5F-0A5C-4C13-B4D6-4BF7836FC9F8}'
CLSID_FileOperation = '{3AD05575-8857-4850-9277-11B85BDB8E09}'

All and all, comtypes, which is a small pure python library, seems quite enough for this task, if one doesn't want to tinker with ctypes, paste in GUID or else doesn't mind the dependency.

However, this is fully implementable in ctypes, as proven by comtypes itself, with the caveat of possibly having to add in GUID manually -

from ctypes import *

BYTE, WORD, DWORD = c_byte, c_ushort, c_ulong

_StringFromCLSID = oledll.ole32.StringFromCLSID
_ProgIDFromCLSID = oledll.ole32.ProgIDFromCLSID
_CLSIDFromString = oledll.ole32.CLSIDFromString
_CLSIDFromProgID = oledll.ole32.CLSIDFromProgID
_CoCreateGuid    = oledll.ole32.CoCreateGuid

_CoTaskMemFree   = windll.ole32.CoTaskMemFree

class GUID(Structure):
    _fields_ = [("Data1", DWORD),
                ("Data2", WORD),
                ("Data3", WORD),
                ("Data4", BYTE * 8)]

    def __init__(self, name=None):
        if name is not None:
            _CLSIDFromString(unicode(name), byref(self))

    def __repr__(self):
        return u'GUID("%s")' % unicode(self)

    def __unicode__(self):
        p = c_wchar_p()
        _StringFromCLSID(byref(self), byref(p))
        result = p.value
        _CoTaskMemFree(p)
        return result
    __str__ = __unicode__

    def __cmp__(self, other):
        if isinstance(other, GUID):
            return cmp(bytes(self), bytes(other))
        return -1

    def __nonzero__(self):
        return self != GUID_null

    def __eq__(self, other):
        return isinstance(other, GUID) and \
               bytes(self) == bytes(other)

    def __hash__(self):
        # We make GUID instances hashable, although they are mutable.
        return hash(bytes(self))

    def copy(self):
        return GUID(unicode(self))

    def from_progid(cls, progid):
        """Get guid from progid, ...
        """
        if hasattr(progid, "_reg_clsid_"):
            progid = progid._reg_clsid_
        if isinstance(progid, cls):
            return progid
        elif isinstance(progid, basestring):
            if progid.startswith("{"):
                return cls(progid)
            inst = cls()
            _CLSIDFromProgID(unicode(progid), byref(inst))
            return inst
        else:
            raise TypeError("Cannot construct guid from %r" % progid)
    from_progid = classmethod(from_progid)

    def as_progid(self):
        "Convert a GUID into a progid"
        progid = c_wchar_p()
        _ProgIDFromCLSID(byref(self), byref(progid))
        result = progid.value
        _CoTaskMemFree(progid)
        return result

    def create_new(cls):
        "Create a brand new guid"
        guid = cls()
        _CoCreateGuid(byref(guid))
        return guid
    create_new = classmethod(create_new)