From 1c823ad98f4fa94fc78bb10246f2414a34a509aa Mon Sep 17 00:00:00 2001
From: Brock <jbrockmendel@gmail.com>
Date: Wed, 22 Sep 2021 12:20:18 -0700
Subject: [PATCH 1/2] REF: DatetimeEngine.__contains__

---
 pandas/_libs/index.pyx | 19 ++++++-------------
 pandas/core/generic.py |  2 ++
 2 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/pandas/_libs/index.pyx b/pandas/_libs/index.pyx
index 31b507e9b7800..82c0132ce1052 100644
--- a/pandas/_libs/index.pyx
+++ b/pandas/_libs/index.pyx
@@ -418,19 +418,12 @@ cdef class DatetimeEngine(Int64Engine):
     def __contains__(self, val: object) -> bool:
         # We assume before we get here:
         #  - val is hashable
-        cdef:
-            int64_t loc, conv
-
-        conv = self._unbox_scalar(val)
-        if self.over_size_threshold and self.is_monotonic_increasing:
-            if not self.is_unique:
-                return self._get_loc_duplicates(conv)
-            values = self.values
-            loc = values.searchsorted(conv, side='left')
-            return values[loc] == conv
-
-        self._ensure_mapping_populated()
-        return conv in self.mapping
+        self._unbox_scalar(val)
+        try:
+            self.get_loc(val)
+            return True
+        except (KeyError, TypeError):
+            return False
 
     cdef _call_monotonic(self, values):
         return algos.is_monotonic(values, timelike=True)
diff --git a/pandas/core/generic.py b/pandas/core/generic.py
index ae5b580c8070d..4321610521f97 100644
--- a/pandas/core/generic.py
+++ b/pandas/core/generic.py
@@ -3953,6 +3953,8 @@ def __delitem__(self, key) -> None:
         maybe_shortcut = False
         if self.ndim == 2 and isinstance(self.columns, MultiIndex):
             try:
+                # By using engine's __contains__ we effectively
+                # restrict to same-length tuples
                 maybe_shortcut = key not in self.columns._engine
             except TypeError:
                 pass

From 8d90a0315af1e7f7d22bfe2fb021ba05cc0fdea2 Mon Sep 17 00:00:00 2001
From: Brock <jbrockmendel@gmail.com>
Date: Wed, 22 Sep 2021 12:55:29 -0700
Subject: [PATCH 2/2] dont catch TypeError

---
 pandas/_libs/index.pyx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/_libs/index.pyx b/pandas/_libs/index.pyx
index 82c0132ce1052..d7de9a25cecda 100644
--- a/pandas/_libs/index.pyx
+++ b/pandas/_libs/index.pyx
@@ -422,7 +422,7 @@ cdef class DatetimeEngine(Int64Engine):
         try:
             self.get_loc(val)
             return True
-        except (KeyError, TypeError):
+        except KeyError:
             return False
 
     cdef _call_monotonic(self, values):