fixes #450

Author: jph00

fastcore/xdg.py

@@ -0,0 +1,72 @@
+# Copyright © 2016-2021 Scott Stevenson <[email protected]>
+# Modifications copyright © 2022 onwards Jeremy Howard
+
+"""XDG Base Directory Specification variables.
+
+xdg_cache_home(), xdg_config_home(), xdg_data_home(), and xdg_state_home()
+return pathlib.Path objects containing the value of the environment variable
+named XDG_CACHE_HOME, XDG_CONFIG_HOME, XDG_DATA_HOME, and XDG_STATE_HOME
+respectively, or the default defined in the specification if the environment
+variable is unset, empty, or contains a relative path rather than absolute
+path.
+
+xdg_config_dirs() and xdg_data_dirs() return a list of pathlib.Path
+objects containing the value, split on colons, of the environment
+variable named XDG_CONFIG_DIRS and XDG_DATA_DIRS respectively, or the
+default defined in the specification if the environment variable is
+unset or empty. Relative paths are ignored, as per the specification.
+
+xdg_runtime_dir() returns a pathlib.Path object containing the value of
+the XDG_RUNTIME_DIR environment variable, or None if the environment
+variable is not set, or contains a relative path rather than absolute path.
+"""
+
+import os
+from pathlib import Path
+from typing import List, Optional
+
+__all__ = [ "xdg_cache_home", "xdg_config_dirs", "xdg_config_home", "xdg_data_dirs", "xdg_data_home", "xdg_runtime_dir", "xdg_state_home",
+    "XDG_CACHE_HOME", "XDG_CONFIG_DIRS", "XDG_CONFIG_HOME", "XDG_DATA_DIRS", "XDG_DATA_HOME", "XDG_RUNTIME_DIR" ]
+
+
+def _path_from_env(variable: str, default: Path) -> Path:
+    value = os.environ.get(variable)
+    if value and os.path.isabs(value): return Path(value)
+    return default
+
+def _paths_from_env(variable: str, default: List[Path]) -> List[Path]:
+    value = os.environ.get(variable)
+    if value:
+        paths = [ Path(path) for path in value.split(":") if os.path.isabs(path) ]
+        if paths: return paths
+    return default
+
+def xdg_cache_home() -> Path:
+    """Path corresponding to XDG_CACHE_HOME."""
+    return _path_from_env("XDG_CACHE_HOME", Path.home()/".cache")
+
+def xdg_config_dirs() -> List[Path]:
+    """Paths corresponding to XDG_CONFIG_DIRS."""
+    return _paths_from_env("XDG_CONFIG_DIRS", [Path("/etc/xdg")])
+
+def xdg_config_home() -> Path:
+    """Path corresponding to XDG_CONFIG_HOME."""
+    return _path_from_env("XDG_CONFIG_HOME", Path.home()/".config")
+
+def xdg_data_dirs() -> List[Path]:
+    """Paths corresponding to XDG_DATA_DIRS."""
+    return _paths_from_env( "XDG_DATA_DIRS", [Path(path) for path in "/usr/local/share/:/usr/share/".split(":")])
+
+def xdg_data_home() -> Path:
+    """Path corresponding to XDG_DATA_HOME."""
+    return _path_from_env("XDG_DATA_HOME", Path.home()/".local"/"share")
+
+def xdg_runtime_dir() -> Optional[Path]:
+    """Path corresponding to XDG_RUNTIME_DIR. """
+    value = os.getenv("XDG_RUNTIME_DIR")
+    return Path(value) if value and os.path.isabs(value) else None
+
+def xdg_state_home() -> Path:
+    """Path corresponding to XDG_STATE_HOME."""
+    return _path_from_env("XDG_STATE_HOME", Path.home()/".local"/"state")
+