From a3f688af99c61c88ddac19b9e72d0a51ea33e1c9 Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Fri, 27 Jul 2018 16:24:50 +0100
Subject: [PATCH 01/20] minor docstring

---
 pandas/core/internals/blocks.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/pandas/core/internals/blocks.py b/pandas/core/internals/blocks.py
index ffa2267dd6877..77208e311b3f3 100644
--- a/pandas/core/internals/blocks.py
+++ b/pandas/core/internals/blocks.py
@@ -777,10 +777,9 @@ def copy(self, deep=True, mgr=None):
 
     def replace(self, to_replace, value, inplace=False, filter=None,
                 regex=False, convert=True, mgr=None):
-        """ replace the to_replace value with value, possible to create new
+        """replace the to_replace value with value, possible to create new
         blocks here this is just a call to putmask. regex is not used here.
-        It is used in ObjectBlocks.  It is here for API
-        compatibility.
+        It is used in ObjectBlocks.  It is here for API compatibility.
         """
 
         inplace = validate_bool_kwarg(inplace, 'inplace')

From c97b2ee954e02077dcb62705cbe3452027067450 Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Fri, 27 Jul 2018 16:45:27 +0100
Subject: [PATCH 02/20] prevent infinite recursion error

---
 pandas/core/generic.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/pandas/core/generic.py b/pandas/core/generic.py
index 16105014bf74e..ebd3804c7dfa0 100644
--- a/pandas/core/generic.py
+++ b/pandas/core/generic.py
@@ -6004,7 +6004,7 @@ def replace(self, to_replace=None, value=None, inplace=False, limit=None,
                 # {'A': NA} -> 0
                 elif not is_list_like(value):
                     keys = [(k, src) for k, src in compat.iteritems(to_replace)
-                            if k in self]
+                            if k in self and len(src) > 0]
                     keys_len = len(keys) - 1
                     for i, (k, src) in enumerate(keys):
                         convert = i == keys_len
@@ -6018,7 +6018,8 @@ def replace(self, to_replace=None, value=None, inplace=False, limit=None,
                     raise TypeError('value argument must be scalar, dict, or '
                                     'Series')
 
-            elif is_list_like(to_replace):  # [NA, ''] -> [0, 'missing']
+            # [NA, ''] -> [0, 'missing']
+            elif is_list_like(to_replace):
                 if is_list_like(value):
                     if len(to_replace) != len(value):
                         raise ValueError('Replacement lists must match '
@@ -6030,7 +6031,8 @@ def replace(self, to_replace=None, value=None, inplace=False, limit=None,
                                                        inplace=inplace,
                                                        regex=regex)
 
-                else:  # [NA, ''] -> 0
+                # [NA, ''] -> 0
+                elif len(to_replace) > 0:
                     new_data = self._data.replace(to_replace=to_replace,
                                                   value=value, inplace=inplace,
                                                   regex=regex)

From 941fccb145a6659eccabd645cc23263fe50b14bf Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Fri, 27 Jul 2018 17:16:20 +0100
Subject: [PATCH 03/20] negative mask if no match or na

---
 pandas/core/missing.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pandas/core/missing.py b/pandas/core/missing.py
index a46c19e2d399c..39081508c575e 100644
--- a/pandas/core/missing.py
+++ b/pandas/core/missing.py
@@ -68,6 +68,9 @@ def mask_missing(arr, values_to_mask):
         else:
             mask |= isna(arr)
 
+    if mask is None:
+        mask = np.zeros(arr.shape, dtype=bool)
+
     return mask
 
 

From 389ebcd4205c444ea26a3d3fbb1de30f79bd5913 Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Fri, 27 Jul 2018 17:16:32 +0100
Subject: [PATCH 04/20] revert generic

---
 pandas/core/generic.py | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/pandas/core/generic.py b/pandas/core/generic.py
index ebd3804c7dfa0..16105014bf74e 100644
--- a/pandas/core/generic.py
+++ b/pandas/core/generic.py
@@ -6004,7 +6004,7 @@ def replace(self, to_replace=None, value=None, inplace=False, limit=None,
                 # {'A': NA} -> 0
                 elif not is_list_like(value):
                     keys = [(k, src) for k, src in compat.iteritems(to_replace)
-                            if k in self and len(src) > 0]
+                            if k in self]
                     keys_len = len(keys) - 1
                     for i, (k, src) in enumerate(keys):
                         convert = i == keys_len
@@ -6018,8 +6018,7 @@ def replace(self, to_replace=None, value=None, inplace=False, limit=None,
                     raise TypeError('value argument must be scalar, dict, or '
                                     'Series')
 
-            # [NA, ''] -> [0, 'missing']
-            elif is_list_like(to_replace):
+            elif is_list_like(to_replace):  # [NA, ''] -> [0, 'missing']
                 if is_list_like(value):
                     if len(to_replace) != len(value):
                         raise ValueError('Replacement lists must match '
@@ -6031,8 +6030,7 @@ def replace(self, to_replace=None, value=None, inplace=False, limit=None,
                                                        inplace=inplace,
                                                        regex=regex)
 
-                # [NA, ''] -> 0
-                elif len(to_replace) > 0:
+                else:  # [NA, ''] -> 0
                     new_data = self._data.replace(to_replace=to_replace,
                                                   value=value, inplace=inplace,
                                                   regex=regex)

From 557365892d5717dda24d35e85c93ac6cdec04f4a Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Sat, 28 Jul 2018 15:25:57 +0100
Subject: [PATCH 05/20] revert missing

---
 pandas/core/missing.py | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/pandas/core/missing.py b/pandas/core/missing.py
index 39081508c575e..a46c19e2d399c 100644
--- a/pandas/core/missing.py
+++ b/pandas/core/missing.py
@@ -68,9 +68,6 @@ def mask_missing(arr, values_to_mask):
         else:
             mask |= isna(arr)
 
-    if mask is None:
-        mask = np.zeros(arr.shape, dtype=bool)
-
     return mask
 
 

From e7dad7e5889373a6eae486ad94e569e0378e7732 Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Sat, 28 Jul 2018 17:47:34 +0100
Subject: [PATCH 06/20] add test case for series.replace

---
 pandas/tests/series/test_replace.py | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/pandas/tests/series/test_replace.py b/pandas/tests/series/test_replace.py
index a3b92798879f5..09ba2e8f204c8 100644
--- a/pandas/tests/series/test_replace.py
+++ b/pandas/tests/series/test_replace.py
@@ -130,6 +130,19 @@ def test_replace_with_single_list(self):
             s.replace([1, 2, 3], inplace=True, method='crash_cymbal')
         tm.assert_series_equal(s, ser)
 
+    def test_replace_with_empty_list(self):
+        # GH 21977
+        s = pd.Series([[1], [2, 3], [], np.nan, [4]])
+        expected = s
+        result = s.replace([], np.nan)
+        tm.assert_series_equal(result, expected)
+
+        # GH 19266
+        with tm.assert_raises_regex(ValueError, 'mismatch length'):
+            s.replace({np.nan: []})
+        with tm.assert_raises_regex(ValueError, 'mismatch length'):
+            s.replace({np.nan: ['dummy', 'alt']})
+
     def test_replace_mixed_types(self):
         s = pd.Series(np.arange(5), dtype='int64')
 

From 309216c982960015c2642bf510ce2006d5bf640b Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Sat, 28 Jul 2018 18:27:38 +0100
Subject: [PATCH 07/20] boolean mask guaranteed if None

---
 pandas/core/missing.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pandas/core/missing.py b/pandas/core/missing.py
index a46c19e2d399c..b2daec327d618 100644
--- a/pandas/core/missing.py
+++ b/pandas/core/missing.py
@@ -68,6 +68,10 @@ def mask_missing(arr, values_to_mask):
         else:
             mask |= isna(arr)
 
+    # GH 21977
+    if mask is None:
+        mask = np.zeros(arr.shape, dtype=bool)
+
     return mask
 
 

From 402d983cb09c8b6af1c0b66dc93c7aa383801fa4 Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Sat, 28 Jul 2018 18:31:16 +0100
Subject: [PATCH 08/20] add test case for frame

---
 pandas/tests/frame/test_replace.py | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/pandas/tests/frame/test_replace.py b/pandas/tests/frame/test_replace.py
index dd83a94b7062a..ad472e19cbec8 100644
--- a/pandas/tests/frame/test_replace.py
+++ b/pandas/tests/frame/test_replace.py
@@ -605,6 +605,20 @@ def test_replace_list(self):
 
         assert_frame_equal(res, expec)
 
+    def test_replace_with_empty_list(self):
+        # GH 21977
+        s = pd.Series([['a', 'b'], np.nan, [1]])
+        df = pd.DataFrame({'col': s})
+
+        expected = df
+        result = df.replace([], np.nan)
+        assert_frame_equal(result, expected)
+        # GH 19266
+        with tm.assert_raises_regex(NotImplementedError, 'Replace with array'):
+            df.replace({np.nan: []})
+        with tm.assert_raises_regex(NotImplementedError, 'Replace with array'):
+            df.replace({np.nan: ['dummy', 'alt']})
+
     def test_replace_series_dict(self):
         # from GH 3064
         df = DataFrame({'zero': {'a': 0.0, 'b': 1}, 'one': {'a': 2.0, 'b': 0}})

From 360403113ca27ab685357bd92d5f7edd2067107d Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Sat, 28 Jul 2018 18:31:30 +0100
Subject: [PATCH 09/20] update series test

---
 pandas/tests/series/test_replace.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/tests/series/test_replace.py b/pandas/tests/series/test_replace.py
index 09ba2e8f204c8..5cf6f283c0fd0 100644
--- a/pandas/tests/series/test_replace.py
+++ b/pandas/tests/series/test_replace.py
@@ -138,9 +138,9 @@ def test_replace_with_empty_list(self):
         tm.assert_series_equal(result, expected)
 
         # GH 19266
-        with tm.assert_raises_regex(ValueError, 'mismatch length'):
+        with tm.assert_raises_regex(NotImplementedError, 'Replace with array'):
             s.replace({np.nan: []})
-        with tm.assert_raises_regex(ValueError, 'mismatch length'):
+        with tm.assert_raises_regex(NotImplementedError, 'Replace with array'):
             s.replace({np.nan: ['dummy', 'alt']})
 
     def test_replace_mixed_types(self):

From 001c3a0d340d61138887af5fb6fc212e3b629611 Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Sat, 28 Jul 2018 18:54:35 +0100
Subject: [PATCH 10/20] use different error to avoid recursion

---
 pandas/core/internals/blocks.py | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/pandas/core/internals/blocks.py b/pandas/core/internals/blocks.py
index 77208e311b3f3..8505a9caf57cb 100644
--- a/pandas/core/internals/blocks.py
+++ b/pandas/core/internals/blocks.py
@@ -992,15 +992,15 @@ def putmask(self, mask, new, align=True, inplace=False, axis=0,
             #
             # TODO: this prob needs some better checking
             # for 2D cases
-            if ((is_list_like(new) and
-                 np.any(mask[mask]) and
+            if ((is_list_like(new) and np.any(mask[mask]) and
                  getattr(new, 'ndim', 1) == 1)):
-
+                # GH 19266 and GH 21977
                 if not (mask.shape[-1] == len(new) or
                         mask[mask].shape[-1] == len(new) or
                         len(new) == 1):
-                    raise ValueError("cannot assign mismatch "
-                                     "length to masked array")
+                    raise NotImplementedError(
+                        "Replace with array-like of mismatch length to masked "
+                        "array is not supported.")
 
             np.putmask(new_values, mask, new)
 

From 91100f7b16e015baf38924e1cfcecc539bb1645d Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Sat, 28 Jul 2018 20:41:26 +0100
Subject: [PATCH 11/20] modify tests to expect intended error

---
 pandas/tests/frame/test_replace.py           | 4 ++--
 pandas/tests/series/indexing/test_boolean.py | 4 ++--
 pandas/tests/series/test_replace.py          | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/pandas/tests/frame/test_replace.py b/pandas/tests/frame/test_replace.py
index ad472e19cbec8..2050f190d875c 100644
--- a/pandas/tests/frame/test_replace.py
+++ b/pandas/tests/frame/test_replace.py
@@ -614,9 +614,9 @@ def test_replace_with_empty_list(self):
         result = df.replace([], np.nan)
         assert_frame_equal(result, expected)
         # GH 19266
-        with tm.assert_raises_regex(NotImplementedError, 'Replace with array'):
+        with tm.assert_raises_regex(Exception, "cannot assign mismatch"):
             df.replace({np.nan: []})
-        with tm.assert_raises_regex(NotImplementedError, 'Replace with array'):
+        with tm.assert_raises_regex(Exception, "cannot assign mismatch"):
             df.replace({np.nan: ['dummy', 'alt']})
 
     def test_replace_series_dict(self):
diff --git a/pandas/tests/series/indexing/test_boolean.py b/pandas/tests/series/indexing/test_boolean.py
index e2a9b3586648d..21337b8cfe51b 100644
--- a/pandas/tests/series/indexing/test_boolean.py
+++ b/pandas/tests/series/indexing/test_boolean.py
@@ -213,12 +213,12 @@ def test_where_unsafe():
     def f():
         s[mask] = [5, 4, 3, 2, 1]
 
-    pytest.raises(ValueError, f)
+    pytest.raises(Exception, f)
 
     def f():
         s[mask] = [0] * 5
 
-    pytest.raises(ValueError, f)
+    pytest.raises(Exception, f)
 
     # dtype changes
     s = Series([1, 2, 3, 4])
diff --git a/pandas/tests/series/test_replace.py b/pandas/tests/series/test_replace.py
index 5cf6f283c0fd0..e3a02aac929dc 100644
--- a/pandas/tests/series/test_replace.py
+++ b/pandas/tests/series/test_replace.py
@@ -138,9 +138,9 @@ def test_replace_with_empty_list(self):
         tm.assert_series_equal(result, expected)
 
         # GH 19266
-        with tm.assert_raises_regex(NotImplementedError, 'Replace with array'):
+        with tm.assert_raises_regex(Exception, "cannot assign mismatch"):
             s.replace({np.nan: []})
-        with tm.assert_raises_regex(NotImplementedError, 'Replace with array'):
+        with tm.assert_raises_regex(Exception, "cannot assign mismatch"):
             s.replace({np.nan: ['dummy', 'alt']})
 
     def test_replace_mixed_types(self):

From 8271576a283fe4b78f967f472063428a9f0c861d Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Sat, 28 Jul 2018 20:42:18 +0100
Subject: [PATCH 12/20] change error type and avoid infinite loop

---
 pandas/core/internals/blocks.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/pandas/core/internals/blocks.py b/pandas/core/internals/blocks.py
index 8505a9caf57cb..5eb74241c204f 100644
--- a/pandas/core/internals/blocks.py
+++ b/pandas/core/internals/blocks.py
@@ -994,13 +994,14 @@ def putmask(self, mask, new, align=True, inplace=False, axis=0,
             # for 2D cases
             if ((is_list_like(new) and np.any(mask[mask]) and
                  getattr(new, 'ndim', 1) == 1)):
-                # GH 19266 and GH 21977
                 if not (mask.shape[-1] == len(new) or
                         mask[mask].shape[-1] == len(new) or
                         len(new) == 1):
-                    raise NotImplementedError(
-                        "Replace with array-like of mismatch length to masked "
-                        "array is not supported.")
+                    # GH 19266 and GH 21977
+                    # ValueError triggers try except block in Block.replace
+                    # causing RecursionError
+                    raise Exception("cannot assign mismatch length "
+                                    "to masked array")
 
             np.putmask(new_values, mask, new)
 

From 167a3b7159d272fcff0b7d03d4108e440b502372 Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Mon, 6 Aug 2018 11:54:15 +0100
Subject: [PATCH 13/20] revert test_boolean

---
 pandas/tests/series/indexing/test_boolean.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/tests/series/indexing/test_boolean.py b/pandas/tests/series/indexing/test_boolean.py
index 21337b8cfe51b..e2a9b3586648d 100644
--- a/pandas/tests/series/indexing/test_boolean.py
+++ b/pandas/tests/series/indexing/test_boolean.py
@@ -213,12 +213,12 @@ def test_where_unsafe():
     def f():
         s[mask] = [5, 4, 3, 2, 1]
 
-    pytest.raises(Exception, f)
+    pytest.raises(ValueError, f)
 
     def f():
         s[mask] = [0] * 5
 
-    pytest.raises(Exception, f)
+    pytest.raises(ValueError, f)
 
     # dtype changes
     s = Series([1, 2, 3, 4])

From f657ae30144d1ffbb1f8c8c621bf986f47ffc813 Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Mon, 6 Aug 2018 11:56:50 +0100
Subject: [PATCH 14/20] revert type of error

---
 pandas/tests/frame/test_replace.py  | 4 ++--
 pandas/tests/series/test_replace.py | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/pandas/tests/frame/test_replace.py b/pandas/tests/frame/test_replace.py
index 2050f190d875c..574c0033d0e3b 100644
--- a/pandas/tests/frame/test_replace.py
+++ b/pandas/tests/frame/test_replace.py
@@ -614,9 +614,9 @@ def test_replace_with_empty_list(self):
         result = df.replace([], np.nan)
         assert_frame_equal(result, expected)
         # GH 19266
-        with tm.assert_raises_regex(Exception, "cannot assign mismatch"):
+        with tm.assert_raises_regex(ValueError, "cannot assign mismatch"):
             df.replace({np.nan: []})
-        with tm.assert_raises_regex(Exception, "cannot assign mismatch"):
+        with tm.assert_raises_regex(ValueError, "cannot assign mismatch"):
             df.replace({np.nan: ['dummy', 'alt']})
 
     def test_replace_series_dict(self):
diff --git a/pandas/tests/series/test_replace.py b/pandas/tests/series/test_replace.py
index e3a02aac929dc..d495fd9c83c24 100644
--- a/pandas/tests/series/test_replace.py
+++ b/pandas/tests/series/test_replace.py
@@ -138,9 +138,9 @@ def test_replace_with_empty_list(self):
         tm.assert_series_equal(result, expected)
 
         # GH 19266
-        with tm.assert_raises_regex(Exception, "cannot assign mismatch"):
+        with tm.assert_raises_regex(ValueError, "cannot assign mismatch"):
             s.replace({np.nan: []})
-        with tm.assert_raises_regex(Exception, "cannot assign mismatch"):
+        with tm.assert_raises_regex(ValueError, "cannot assign mismatch"):
             s.replace({np.nan: ['dummy', 'alt']})
 
     def test_replace_mixed_types(self):

From c8f4f72f74684084b6f4e11f3e1cf6407a053784 Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Mon, 6 Aug 2018 12:04:24 +0100
Subject: [PATCH 15/20] only retry if the block is not ObjectBlock

---
 pandas/core/internals/blocks.py | 28 ++++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/pandas/core/internals/blocks.py b/pandas/core/internals/blocks.py
index 5eb74241c204f..34437760c1ab8 100644
--- a/pandas/core/internals/blocks.py
+++ b/pandas/core/internals/blocks.py
@@ -801,12 +801,17 @@ def replace(self, to_replace, value, inplace=False, filter=None,
                                     copy=not inplace) for b in blocks]
             return blocks
         except (TypeError, ValueError):
-
-            # try again with a compatible block
-            block = self.astype(object)
-            return block.replace(
-                to_replace=original_to_replace, value=value, inplace=inplace,
-                filter=filter, regex=regex, convert=convert)
+            if self.dtype == 'object':
+                raise
+            else:
+                # try again with a compatible block
+                block = self.astype(object)
+                return block.replace(to_replace=original_to_replace,
+                                     value=value,
+                                     inplace=inplace,
+                                     filter=filter,
+                                     regex=regex,
+                                     convert=convert)
 
     def _replace_single(self, *args, **kwargs):
         """ no-op on a non-ObjectBlock """
@@ -992,16 +997,15 @@ def putmask(self, mask, new, align=True, inplace=False, axis=0,
             #
             # TODO: this prob needs some better checking
             # for 2D cases
-            if ((is_list_like(new) and np.any(mask[mask]) and
+            if ((is_list_like(new) and
+                 np.any(mask[mask]) and
                  getattr(new, 'ndim', 1) == 1)):
+
                 if not (mask.shape[-1] == len(new) or
                         mask[mask].shape[-1] == len(new) or
                         len(new) == 1):
-                    # GH 19266 and GH 21977
-                    # ValueError triggers try except block in Block.replace
-                    # causing RecursionError
-                    raise Exception("cannot assign mismatch length "
-                                    "to masked array")
+                    raise ValueError("cannot assign mismatch "
+                                     "length to masked array")
 
             np.putmask(new_values, mask, new)
 

From d3c3236730efc9e6ddf1c34568b76753d24454f2 Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Mon, 6 Aug 2018 12:09:37 +0100
Subject: [PATCH 16/20] add comment

---
 pandas/core/internals/blocks.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pandas/core/internals/blocks.py b/pandas/core/internals/blocks.py
index 34437760c1ab8..4537428e04f77 100644
--- a/pandas/core/internals/blocks.py
+++ b/pandas/core/internals/blocks.py
@@ -801,6 +801,8 @@ def replace(self, to_replace, value, inplace=False, filter=None,
                                     copy=not inplace) for b in blocks]
             return blocks
         except (TypeError, ValueError):
+            # GH 22083, TypeError or ValueError occurred within error handling
+            # causes infinite loop. Cast and retry only if not objectblock.
             if self.dtype == 'object':
                 raise
             else:

From a8020b98dbcafe5cd61ac792cec2fedb00de8c4d Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Mon, 6 Aug 2018 14:31:21 +0100
Subject: [PATCH 17/20] add whatsnew

---
 doc/source/whatsnew/v0.24.0.txt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/doc/source/whatsnew/v0.24.0.txt b/doc/source/whatsnew/v0.24.0.txt
index ea0677a0edf28..695a775110c73 100644
--- a/doc/source/whatsnew/v0.24.0.txt
+++ b/doc/source/whatsnew/v0.24.0.txt
@@ -667,7 +667,8 @@ Reshaping
 - Bug in :meth:`DataFrame.replace` raises RecursionError when converting OutOfBounds ``datetime64[ns, tz]`` (:issue:`20380`)
 - :func:`pandas.core.groupby.GroupBy.rank` now raises a ``ValueError`` when an invalid value is passed for argument ``na_option`` (:issue:`22124`)
 - Bug in :func:`get_dummies` with Unicode attributes in Python 2 (:issue:`22084`)
--
+- Bug in :meth:`DataFrame.replace` raises RecursionError when replace empty lists (:issue:`22083`)
+- 
 
 Build Changes
 ^^^^^^^^^^^^^

From 201adf6c42cab132b989aad0cad461d6fd5db4fb Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Mon, 6 Aug 2018 17:37:35 +0100
Subject: [PATCH 18/20] minor change in whatsnew

---
 doc/source/whatsnew/v0.24.0.txt | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/source/whatsnew/v0.24.0.txt b/doc/source/whatsnew/v0.24.0.txt
index 695a775110c73..7c46a1c7b7f27 100644
--- a/doc/source/whatsnew/v0.24.0.txt
+++ b/doc/source/whatsnew/v0.24.0.txt
@@ -667,8 +667,8 @@ Reshaping
 - Bug in :meth:`DataFrame.replace` raises RecursionError when converting OutOfBounds ``datetime64[ns, tz]`` (:issue:`20380`)
 - :func:`pandas.core.groupby.GroupBy.rank` now raises a ``ValueError`` when an invalid value is passed for argument ``na_option`` (:issue:`22124`)
 - Bug in :func:`get_dummies` with Unicode attributes in Python 2 (:issue:`22084`)
-- Bug in :meth:`DataFrame.replace` raises RecursionError when replace empty lists (:issue:`22083`)
-- 
+- Bug in :meth:`DataFrame.replace` raises ``RecursionError`` when replacing empty lists (:issue:`22083`)
+-
 
 Build Changes
 ^^^^^^^^^^^^^

From c4a4a8bf060b6d5d216d7f74c44f58b9314ee23f Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Mon, 6 Aug 2018 17:41:05 +0100
Subject: [PATCH 19/20] add empty list

---
 pandas/tests/frame/test_replace.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/tests/frame/test_replace.py b/pandas/tests/frame/test_replace.py
index 6e7e76d15c15e..49dba1c769572 100644
--- a/pandas/tests/frame/test_replace.py
+++ b/pandas/tests/frame/test_replace.py
@@ -605,12 +605,12 @@ def test_replace_list(self):
 
     def test_replace_with_empty_list(self):
         # GH 21977
-        s = pd.Series([['a', 'b'], np.nan, [1]])
+        s = pd.Series([['a', 'b'], [], np.nan, [1]])
         df = pd.DataFrame({'col': s})
-
         expected = df
         result = df.replace([], np.nan)
         assert_frame_equal(result, expected)
+
         # GH 19266
         with tm.assert_raises_regex(ValueError, "cannot assign mismatch"):
             df.replace({np.nan: []})

From 2bbd097f8a5ed6f1eeb487461a5a6820277a1a4d Mon Sep 17 00:00:00 2001
From: Ming Li <ming.george.li@gmail.com>
Date: Tue, 7 Aug 2018 14:23:19 +0100
Subject: [PATCH 20/20] minor refactor

---
 pandas/core/internals/blocks.py | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/pandas/core/internals/blocks.py b/pandas/core/internals/blocks.py
index 46ae439d973d4..be80a605f08fd 100644
--- a/pandas/core/internals/blocks.py
+++ b/pandas/core/internals/blocks.py
@@ -803,17 +803,17 @@ def replace(self, to_replace, value, inplace=False, filter=None,
         except (TypeError, ValueError):
             # GH 22083, TypeError or ValueError occurred within error handling
             # causes infinite loop. Cast and retry only if not objectblock.
-            if self.dtype == 'object':
+            if is_object_dtype(self):
                 raise
-            else:
-                # try again with a compatible block
-                block = self.astype(object)
-                return block.replace(to_replace=original_to_replace,
-                                     value=value,
-                                     inplace=inplace,
-                                     filter=filter,
-                                     regex=regex,
-                                     convert=convert)
+
+            # try again with a compatible block
+            block = self.astype(object)
+            return block.replace(to_replace=original_to_replace,
+                                 value=value,
+                                 inplace=inplace,
+                                 filter=filter,
+                                 regex=regex,
+                                 convert=convert)
 
     def _replace_single(self, *args, **kwargs):
         """ no-op on a non-ObjectBlock """