From e5a32ca0e814933a74634b2d6db4647de58815ac Mon Sep 17 00:00:00 2001
From: Patrick Hoefler <patrick_hoefler@gmx.net>
Date: Sun, 28 Aug 2022 13:48:33 +0200
Subject: [PATCH] TYP: Specify how in dropna

---
 pandas/core/frame.py         |  6 +++---
 pandas/core/indexes/base.py  |  2 +-
 pandas/core/indexes/multi.py |  2 +-
 pandas/core/series.py        | 17 ++++++++++++++---
 4 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/pandas/core/frame.py b/pandas/core/frame.py
index 4302b14da6418..52b5dd87f58f4 100644
--- a/pandas/core/frame.py
+++ b/pandas/core/frame.py
@@ -6423,7 +6423,7 @@ def dropna(
         self,
         *,
         axis: Axis = ...,
-        how: str | NoDefault = ...,
+        how: Literal["any", "all"] | NoDefault = ...,
         thresh: int | NoDefault = ...,
         subset: IndexLabel = ...,
         inplace: Literal[False] = ...,
@@ -6435,7 +6435,7 @@ def dropna(
         self,
         *,
         axis: Axis = ...,
-        how: str | NoDefault = ...,
+        how: Literal["any", "all"] | NoDefault = ...,
         thresh: int | NoDefault = ...,
         subset: IndexLabel = ...,
         inplace: Literal[True],
@@ -6446,7 +6446,7 @@ def dropna(
     def dropna(
         self,
         axis: Axis = 0,
-        how: str | NoDefault = no_default,
+        how: Literal["any", "all"] | NoDefault = no_default,
         thresh: int | NoDefault = no_default,
         subset: IndexLabel = None,
         inplace: bool = False,
diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 91c658a4cef5d..88f3de52276da 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -2971,7 +2971,7 @@ def fillna(self, value=None, downcast=None):
             )
         return self._view()
 
-    def dropna(self: _IndexT, how: str_t = "any") -> _IndexT:
+    def dropna(self: _IndexT, how: Literal["any", "all"] = "any") -> _IndexT:
         """
         Return Index without NA/NaN values.
 
diff --git a/pandas/core/indexes/multi.py b/pandas/core/indexes/multi.py
index 63c78b7002786..c524a448ae045 100644
--- a/pandas/core/indexes/multi.py
+++ b/pandas/core/indexes/multi.py
@@ -1634,7 +1634,7 @@ def fillna(self, value=None, downcast=None):
         raise NotImplementedError("isna is not defined for MultiIndex")
 
     @doc(Index.dropna)
-    def dropna(self, how: str = "any") -> MultiIndex:
+    def dropna(self, how: Literal["any", "all"] = "any") -> MultiIndex:
         nans = [level_codes == -1 for level_codes in self.codes]
         if how == "any":
             indexer = np.any(nans, axis=0)
diff --git a/pandas/core/series.py b/pandas/core/series.py
index d2f66e9bd36e2..1978caccec339 100644
--- a/pandas/core/series.py
+++ b/pandas/core/series.py
@@ -5731,19 +5731,30 @@ def notnull(self) -> Series:
 
     @overload
     def dropna(
-        self, *, axis: Axis = ..., inplace: Literal[False] = ..., how: str | None = ...
+        self,
+        *,
+        axis: Axis = ...,
+        inplace: Literal[False] = ...,
+        how: Literal["any", "all"] | None = ...,
     ) -> Series:
         ...
 
     @overload
     def dropna(
-        self, *, axis: Axis = ..., inplace: Literal[True], how: str | None = ...
+        self,
+        *,
+        axis: Axis = ...,
+        inplace: Literal[True],
+        how: Literal["any", "all"] | None = ...,
     ) -> None:
         ...
 
     @deprecate_nonkeyword_arguments(version=None, allowed_args=["self"])
     def dropna(
-        self, axis: Axis = 0, inplace: bool = False, how: str | None = None
+        self,
+        axis: Axis = 0,
+        inplace: bool = False,
+        how: Literal["any", "all"] | None = None,
     ) -> Series | None:
         """
         Return a new Series with missing values removed.