pywintypes.py: DeprecationWarning: getargs: The 'u' format is deprecated. Use 'U' instead.

[jiasli]

• Expected behavior and actual behavior.

No DeprecationWarning should be shown.

• Steps to reproduce the problem.

> cat test_pywin32.py
def test_pywin32():
    import pywintypes

> pytest .\test_pywin32.py
===================================================== test session starts =====================================================
platform win32 -- Python 3.10.0, pytest-6.2.5, py-1.11.0, pluggy-1.0.0
rootdir: D:\cli\testproj
plugins: forked-1.3.0, xdist-2.4.0
collected 1 item

test_pywin32.py .                                                                                                        [100%]

====================================================== warnings summary =======================================================
test_pywin32.py::test_pywin32
  D:\cli\py310\lib\site-packages\win32\lib\pywintypes.py:54: DeprecationWarning: getargs: The 'u' format is deprecated. Use 'U' instead.
    found = _win32sysloader.GetModuleFilename(filename)

test_pywin32.py::test_pywin32
  D:\cli\py310\lib\site-packages\win32\lib\pywintypes.py:68: DeprecationWarning: getargs: The 'u' format is deprecated. Use 'U' instead.
    found = _win32sysloader.LoadModule(filename)

-- Docs: https://docs.pytest.org/en/stable/warnings.html
================================================ 1 passed, 2 warnings in 0.13s ================================================

• Version of Python and pywin32

> python -V
Python 3.10.0

> pip list | Select-String pywin32

pywin32                                 302

[juliangilbey]

I'm seeing the same issue, but I don't have pywin32 installed and I'm not running on a Windows machine. There's some other underlying cause of this DeprecationWarning, but I don't know where it is.

[Tolker-KU]

I've done a bit of digging. This warnings seems to come from passing "u" as a format string to PyArg_ParseTuple here:

pywin32/win32/src/_win32sysloader.cpp

Lines 20 to 31 in 7adb18f

	static PyObject *PyGetModuleFilename(PyObject *self, PyObject *args)
	{
	// For py3k, will be built with UNICODE defined
	#ifdef UNICODE
	static char *fmt = "u";
	#else
	static char *fmt = "s";
	#endif
	TCHAR *modName = NULL;
	if (!PyArg_ParseTuple(args, fmt, &modName))
	return NULL;

and/or here:

pywin32/win32/src/_win32sysloader.cpp

Lines 49 to 58 in 7adb18f

	static PyObject *PyLoadModule(PyObject *self, PyObject *args)
	{
	#ifdef UNICODE
	static char *fmt = "u";
	#else
	static char *fmt = "s";
	#endif
	TCHAR *modName = NULL;
	if (!PyArg_ParseTuple(args, fmt, &modName))
	return NULL;

Which is deprecated.

Actually solving it and making a PR is the next step

[liudonghua123]

I have the same warning, I use python 3.10. And the version of pywin32 installed is 303 which is the latest currently. I hope the new release which fixed this warning could release soon.

From the doc https://docs.python.org/3/c-api/arg.html#strings-and-buffers, I find the following text.

u (str) [const Py_UNICODE *]
Convert a Python Unicode object to a C pointer to a NUL-terminated buffer of Unicode characters. You must pass the address of a Py_UNICODE pointer variable, which will be filled with the pointer to an existing Unicode buffer. Please note that the width of a Py_UNICODE character depends on compilation options (it is either 16 or 32 bits). The Python string must not contain embedded null code points; if it does, a ValueError exception is raised.

Changed in version 3.5: Previously, TypeError was raised when embedded null code points were encountered in the Python string.

Deprecated since version 3.3, will be removed in version 3.12: Part of the old-style Py_UNICODE API; please migrate to using PyUnicode_AsWideCharString().

The 'u' format is already deprecated since 3.3.