Installing Python wrapper on Windows, cannot find .dll files

[atmosalex]

Hi, I successfully built IRBEM following the instructions to make libirbem.dll. Then I installed the Python wrapper by running pip install -e . from the IRBEM\python directory

First minor issue: some of the .dll dependencies are not in the correct place: running ldd .\libirbem.dll shows incorrect paths. I managed to fix this by creating symbolic links. This might be an issue with my environment rather than IRBEM.

However, the main issue is, the code:

import IRBEM as ib
a = ib.Coords()

results in this error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\IRBEM\python\IRBEM\IRBEM.py", line 1005, in __init__
    self.path, self._irbem_obj = _load_shared_object(self.irbem_obj_path)
                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\IRBEM\python\IRBEM\IRBEM.py", line 1170, in _load_shared_object
    _irbem_obj = ctypes.WinDLL(str(path))
                 ^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Alex\.conda\envs\atm\Lib\ctypes\__init__.py", line 376, in __init__
    self._handle = _dlopen(self._name, mode)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: [WinError 127] The specified procedure could not be found

This is not an issue with IRBEM itself, it is caused because ctypes cannot find the dll's. I believe it might be because since Python 3.8, the system's standard PATH variable is no longer used to search for dll dependencies.

I managed to fix this issue by adding the following lines of code to my script before importing IRBEM:

os.add_dll_directory("/WINDOWS/SYSTEM32")
os.add_dll_directory("/Users/Alex/.conda/envs/atm/Library/mingw-w64/bin")
os.add_dll_directory("/ucrt64/bin")
os.add_dll_directory("/WINDOWS/System32")

Obviously these relate to my environment and this method is not a real fix. However I thought explaining my issues here might help to make IRBEM easier to install in the future.

[atmosalex]

Slightly more useful solution: since IRBEM was installed using editable mode, I just added this function and call to the top of IRBEM.py, after the import os line:

def add_path_to_dll_directories():
    # Only applicable for Windows and Python 3.8+
    if os.name == 'nt' and hasattr(os, 'add_dll_directory'):
        # Get the PATH environment variable and split it by the separator (';')
        path_env = os.environ.get('PATH', '')
        directories = path_env.split(os.pathsep)

        for directory in directories:
            # Check if the directory exists before adding it to avoid errors
            if os.path.isdir(directory):
                try:
                    os.add_dll_directory(directory)
                    #print(f"Added DLL directory: {directory}")
                except Exception as e:
                    #print(f"Could not add {directory}: {e}")
                    pass
    else:
        print("os.add_dll_directory is not supported on this platform/version.")
add_path_to_dll_directories()