bpo-23082: Better error message for PurePath.relative_to() from pathlib (GH-19611)
Co-authored-by: Sadhana Srinivasan <rotuna@Sadhanas-MBP.fritz.box>
(cherry picked from commit 448325369ff73011d34d6c3a493014fe3ead8843)
Co-authored-by: Rotuna <sadhanasrinivasan@protonmail.com>
diff --git a/Lib/pathlib.py b/Lib/pathlib.py
index f98d69e..9f5e27b 100644
--- a/Lib/pathlib.py
+++ b/Lib/pathlib.py
@@ -922,7 +922,8 @@
cf = self._flavour.casefold_parts
if (root or drv) if n == 0 else cf(abs_parts[:n]) != cf(to_abs_parts):
formatted = self._format_parsed_parts(to_drv, to_root, to_parts)
- raise ValueError("{!r} does not start with {!r}"
+ raise ValueError("{!r} is not in the subpath of {!r}"
+ " OR one path is relative and the other is absolute."
.format(str(self), str(formatted)))
return self._from_parsed_parts('', root if n == 1 else '',
abs_parts[n:])