diff --git a/pandas/_typing.py b/pandas/_typing.py
index 445eff9e19e47..e480933e9da39 100644
--- a/pandas/_typing.py
+++ b/pandas/_typing.py
@@ -23,6 +23,7 @@
     from pandas.core.indexes.base import Index  # noqa: F401
     from pandas.core.series import Series  # noqa: F401
     from pandas.core.generic import NDFrame  # noqa: F401
+    from pandas.io.formats.style import Styler  # noqa: F401
 
 
 AnyArrayLike = TypeVar("AnyArrayLike", "ExtensionArray", "Index", "Series", np.ndarray)
diff --git a/pandas/core/frame.py b/pandas/core/frame.py
index fde3d1657b4f2..08ad92478c67c 100644
--- a/pandas/core/frame.py
+++ b/pandas/core/frame.py
@@ -84,7 +84,7 @@
 )
 from pandas.core.dtypes.missing import isna, notna
 
-from pandas._typing import Axes, Dtype, FilePathOrBuffer
+from pandas._typing import Axes, Dtype, FilePathOrBuffer, Styler
 from pandas.core import algorithms, common as com, nanops, ops
 from pandas.core.accessor import CachedAccessor
 from pandas.core.arrays import Categorical, ExtensionArray
@@ -804,7 +804,7 @@ def to_string(
     # ----------------------------------------------------------------------
 
     @property
-    def style(self):
+    def style(self) -> "Styler":
         """
         Returns a Styler object.
 
@@ -882,7 +882,7 @@ def items(self) -> Iterable[Tuple[Optional[Hashable], Series]]:
     def iteritems(self):
         yield from self.items()
 
-    def iterrows(self):
+    def iterrows(self) -> Iterable[Tuple[Index, Series]]:
         """
         Iterate over DataFrame rows as (index, Series) pairs.
 
@@ -1020,7 +1020,7 @@ def __len__(self) -> int:
         """
         return len(self.index)
 
-    def dot(self, other):
+    def dot(self, other: Union[Series, DataFrame]) -> Union[Series, DataFrame]:
         """
         Compute the matrix multiplication between the DataFrame and other.
 
@@ -1131,13 +1131,13 @@ def dot(self, other):
         else:  # pragma: no cover
             raise TypeError("unsupported type: {oth}".format(oth=type(other)))
 
-    def __matmul__(self, other):
+    def __matmul__(self, other: Union[Series, DataFrame]) -> Union[Series, DataFrame]:
         """
         Matrix multiplication using binary `@` operator in Python>=3.5.
         """
         return self.dot(other)
 
-    def __rmatmul__(self, other):
+    def __rmatmul__(self, other: Union[Series, DataFrame]) -> Union[Series, DataFrame]:
         """
         Matrix multiplication using binary `@` operator in Python>=3.5.
         """
@@ -4631,7 +4631,7 @@ def drop_duplicates(self, subset=None, keep="first", inplace=False):
         duplicated = self.duplicated(subset, keep=keep)
 
         if inplace:
-            (inds,) = (-duplicated)._ndarray_values.nonzero()
+            inds = (-duplicated)._ndarray_values.nonzero()[0]
             new_data = self._data.take(inds)
             self._update_inplace(new_data)
         else: