chore: import upstream snapshot with attribution

python-package/lightgbm/libpath.py

@@ -0,0 +1,49 @@
+# coding: utf-8
+"""Find the path to LightGBM dynamic library files."""
+
+import ctypes
+from os import environ
+from pathlib import Path
+from platform import system
+from typing import List
+
+__all__: List[str] = []
+
+
+def _find_lib_path() -> List[str]:
+    """Find the path to LightGBM library files.
+
+    Returns
+    -------
+    lib_path: list of str
+       List of all found library paths to LightGBM.
+    """
+    curr_path = Path(__file__).resolve()
+    dll_path = [
+        curr_path.parents[1],
+        curr_path.parents[0] / "bin",
+        curr_path.parents[0] / "lib",
+    ]
+    if system() in ("Windows", "Microsoft"):
+        dll_path.append(curr_path.parents[1] / "Release")
+        dll_path.append(curr_path.parents[1] / "windows" / "x64" / "DLL")
+        dll_path = [p / "lib_lightgbm.dll" for p in dll_path]
+    elif system() == "Darwin":
+        dll_path = [p / "lib_lightgbm.dylib" for p in dll_path]
+    else:
+        dll_path = [p / "lib_lightgbm.so" for p in dll_path]
+    lib_path = [str(p) for p in dll_path if p.is_file()]
+    if not lib_path:
+        dll_path_joined = "\n".join(map(str, dll_path))
+        raise Exception(f"Cannot find lightgbm library file in following paths:\n{dll_path_joined}")
+    return lib_path
+
+
+# we don't need lib_lightgbm while building docs
+_LIB: ctypes.CDLL
+if environ.get("LIGHTGBM_BUILD_DOC", "False") == "True":
+    from unittest.mock import Mock  # isort: skip
+
+    _LIB = Mock(ctypes.CDLL)  # type: ignore
+else:
+    _LIB = ctypes.cdll.LoadLibrary(_find_lib_path()[0])