trace the stack when root finding gets desperate

src/root.py

@@ -1,11 +1,28 @@
 #! /usr/bin/env python3
 
+import inspect
 import os
-from pathlib import Path
+import sys
 from importlib.resources import files
+from pathlib import Path
+from typing import Optional
+
 import __main__
 
 
+def walk_stack() -> Optional[Path]:
+    stack = inspect.stack()
+    i = 0
+    file_name = "<>"
+    while -i <= len(stack) and file_name[0] == "<" and file_name[-1] == ">":
+        i -= 1
+        file_name = stack[i].filename
+
+    if file_name[0] == "<" and file_name[-1] == ">":
+        return None
+    return Path(file_name)
+
+
 def root_dir():
     if "FILE_PATH" in os.environ:
         return Path(os.environ["FILE_PATH"]).parent()
@@ -13,19 +30,22 @@ def root_dir():
     if __main__.__package__:
         return files(__main__.__package__)
 
-    # Use the folder of the main file as toml_dir.
     if "__file__" in dir(__main__):
-        toml_dir = Path(__main__.__file__).parent
+        return Path(__main__.__file__).parent
-        return toml_dir
 
     # Find the path of the ipython notebook.
     try:
+        get_ipython()
         import ipynbname
 
         return ipynbname.path().parent
-    except IndexError:
+    except (NameError, IndexError):
         pass
 
+    out = walk_stack()
+    if out:
+        return out.parent
+
     return Path(os.path.abspath("."))
 
 
@@ -36,14 +56,22 @@ def root_file():
     if "FILE_NAME" in os.environ:
         return root_dir() / os.environ["FILE_NAME"]
 
+    if __main__.__package__:
+        return files(__main__.__package__).joinpath("__main__.py")
+
     if "__file__" in dir(__main__):
         return Path(__main__.__file__)
 
     try:
+        get_ipython()
         import ipynbname
 
         return ipynbname.path()
-    except IndexError:
+    except (NameError, IndexError):
         pass
 
+    out = walk_stack()
+    if out:
+        return out
+
     raise NotImplementedError