From dace3f069b94ffdf8b9d5107ca206e4fb6b9bcae Mon Sep 17 00:00:00 2001
From: Brock <jbrockmendel@gmail.com>
Date: Wed, 16 Sep 2020 21:04:31 -0700
Subject: [PATCH] REF: re-use _maybe_promote for
 _is_convertible_to_index_for_join

---
 pandas/core/indexes/datetimelike.py | 29 +++++------------------------
 1 file changed, 5 insertions(+), 24 deletions(-)

diff --git a/pandas/core/indexes/datetimelike.py b/pandas/core/indexes/datetimelike.py
index 5ba5732c710f7..dc427495b6cb1 100644
--- a/pandas/core/indexes/datetimelike.py
+++ b/pandas/core/indexes/datetimelike.py
@@ -865,11 +865,11 @@ def join(
         """
         See Index.join
         """
-        if self._is_convertible_to_index_for_join(other):
-            try:
-                other = type(self)(other)
-            except (TypeError, ValueError):
-                pass
+        pself, pother = self._maybe_promote(other)
+        if pself is not self or pother is not other:
+            return pself.join(
+                pother, how=how, level=level, return_indexers=return_indexers, sort=sort
+            )
 
         this, other = self._maybe_utc_convert(other)
         return Index.join(
@@ -898,25 +898,6 @@ def _maybe_utc_convert(self, other):
                 other = other.tz_convert("UTC")
         return this, other
 
-    @classmethod
-    def _is_convertible_to_index_for_join(cls, other: Index) -> bool:
-        """
-        return a boolean whether I can attempt conversion to a
-        DatetimeIndex/TimedeltaIndex
-        """
-        if isinstance(other, cls):
-            return False
-        elif len(other) > 0 and other.inferred_type not in (
-            "floating",
-            "mixed-integer",
-            "integer",
-            "integer-na",
-            "mixed-integer-float",
-            "mixed",
-        ):
-            return True
-        return False
-
     # --------------------------------------------------------------------
     # List-Like Methods