From bc1c21ac9ff3c343f004c151ecfe3fdae7befb3a Mon Sep 17 00:00:00 2001
From: jbrockmendel <jbrockmendel@gmail.com>
Date: Wed, 17 Jul 2019 15:30:27 -0700
Subject: [PATCH 01/10] validate args for maybe_convert_objects,
 soft_convert_objects; remove unreachable branches

---
 pandas/core/dtypes/cast.py | 83 +++++++++++++++-----------------------
 pandas/core/generic.py     |  5 +++
 2 files changed, 37 insertions(+), 51 deletions(-)

diff --git a/pandas/core/dtypes/cast.py b/pandas/core/dtypes/cast.py
index f483cf520754b..f4f0f34764272 100644
--- a/pandas/core/dtypes/cast.py
+++ b/pandas/core/dtypes/cast.py
@@ -6,6 +6,7 @@
 
 from pandas._libs import lib, tslib, tslibs
 from pandas._libs.tslibs import NaT, OutOfBoundsDatetime, Period, iNaT
+from pandas.util._validators import validate_bool_kwarg
 
 from .common import (
     _INT64_DTYPE,
@@ -708,9 +709,7 @@ def astype_nansafe(arr, dtype, copy=True, skipna=False):
     elif np.issubdtype(arr.dtype, np.floating) and np.issubdtype(dtype, np.integer):
 
         if not np.isfinite(arr).all():
-            raise ValueError(
-                "Cannot convert non-finite values (NA or inf) to " "integer"
-            )
+            raise ValueError("Cannot convert non-finite values (NA or inf) to integer")
 
     elif is_object_dtype(arr):
 
@@ -731,9 +730,7 @@ def astype_nansafe(arr, dtype, copy=True, skipna=False):
             return astype_nansafe(to_timedelta(arr).values, dtype, copy=copy)
 
     if dtype.name in ("datetime64", "timedelta64"):
-        msg = (
-            "The '{dtype}' dtype has no unit. " "Please pass in '{dtype}[ns]' instead."
-        )
+        msg = "The '{dtype}' dtype has no unit. Please pass in '{dtype}[ns]' instead."
         raise ValueError(msg.format(dtype=dtype.name))
 
     if copy or is_object_dtype(arr) or is_object_dtype(dtype):
@@ -744,46 +741,25 @@ def astype_nansafe(arr, dtype, copy=True, skipna=False):
 
 
 def maybe_convert_objects(
-    values, convert_dates=True, convert_numeric=True, convert_timedeltas=True, copy=True
+    values: np.ndarray,
+    convert_dates: bool = True,
+    convert_numeric: bool = True,
+    convert_timedeltas: bool = True,
+    copy: bool = True,
 ):
     """ if we have an object dtype, try to coerce dates and/or numbers """
-
-    # if we have passed in a list or scalar
-    if isinstance(values, (list, tuple)):
-        values = np.array(values, dtype=np.object_)
-    if not hasattr(values, "dtype"):
-        values = np.array([values], dtype=np.object_)
+    validate_bool_kwarg(convert_dates, "convert_dates")
+    validate_bool_kwarg(convert_numeric, "convert_numeric")
+    validate_bool_kwarg(convert_timedeltas, "convert_timedeltas")
+    validate_bool_kwarg(copy, "copy")
 
     # convert dates
     if convert_dates and values.dtype == np.object_:
-
-        # we take an aggressive stance and convert to datetime64[ns]
-        if convert_dates == "coerce":
-            new_values = maybe_cast_to_datetime(values, "M8[ns]", errors="coerce")
-
-            # if we are all nans then leave me alone
-            if not isna(new_values).all():
-                values = new_values
-
-        else:
-            values = lib.maybe_convert_objects(values, convert_datetime=convert_dates)
+        values = lib.maybe_convert_objects(values, convert_datetime=True)
 
     # convert timedeltas
     if convert_timedeltas and values.dtype == np.object_:
-
-        if convert_timedeltas == "coerce":
-            from pandas.core.tools.timedeltas import to_timedelta
-
-            new_values = to_timedelta(values, errors="coerce")
-
-            # if we are all nans then leave me alone
-            if not isna(new_values).all():
-                values = new_values
-
-        else:
-            values = lib.maybe_convert_objects(
-                values, convert_timedelta=convert_timedeltas
-            )
+        values = lib.maybe_convert_objects(values, convert_timedelta=True)
 
     # convert to numeric
     if values.dtype == np.object_:
@@ -809,27 +785,32 @@ def maybe_convert_objects(
 
 
 def soft_convert_objects(
-    values, datetime=True, numeric=True, timedelta=True, coerce=False, copy=True
+    values: np.ndarray,
+    datetime: bool = True,
+    numeric: bool = True,
+    timedelta: bool = True,
+    coerce: bool = False,
+    copy: bool = True,
 ):
     """ if we have an object dtype, try to coerce dates and/or numbers """
 
+    validate_bool_kwarg(datetime, "datetime")
+    validate_bool_kwarg(numeric, "numeric")
+    validate_bool_kwarg(timedelta, "timedelta")
+    validate_bool_kwarg(coerce, "coerce")
+    validate_bool_kwarg(copy, "copy")
+    assert not coerce  # we're only called from one place in internals.blocks
+
     conversion_count = sum((datetime, numeric, timedelta))
     if conversion_count == 0:
-        raise ValueError(
-            "At least one of datetime, numeric or timedelta must " "be True."
-        )
+        raise ValueError("At least one of datetime, numeric or timedelta must be True.")
     elif conversion_count > 1 and coerce:
         raise ValueError(
             "Only one of 'datetime', 'numeric' or "
             "'timedelta' can be True when when coerce=True."
         )
 
-    if isinstance(values, (list, tuple)):
-        # List or scalar
-        values = np.array(values, dtype=np.object_)
-    elif not hasattr(values, "dtype"):
-        values = np.array([values], dtype=np.object_)
-    elif not is_object_dtype(values.dtype):
+    if not is_object_dtype(values.dtype):
         # If not object, do not attempt conversion
         values = values.copy() if copy else values
         return values
@@ -855,13 +836,13 @@ def soft_convert_objects(
         # GH 20380, when datetime is beyond year 2262, hence outside
         # bound of nanosecond-resolution 64-bit integers.
         try:
-            values = lib.maybe_convert_objects(values, convert_datetime=datetime)
+            values = lib.maybe_convert_objects(values, convert_datetime=True)
         except OutOfBoundsDatetime:
             pass
 
     if timedelta and is_object_dtype(values.dtype):
         # Object check to ensure only run if previous did not convert
-        values = lib.maybe_convert_objects(values, convert_timedelta=timedelta)
+        values = lib.maybe_convert_objects(values, convert_timedelta=True)
 
     if numeric and is_object_dtype(values.dtype):
         try:
@@ -1380,7 +1361,7 @@ def maybe_cast_to_integer_array(arr, dtype, copy=False):
     arr = np.asarray(arr)
 
     if is_unsigned_integer_dtype(dtype) and (arr < 0).any():
-        raise OverflowError("Trying to coerce negative values " "to unsigned integers")
+        raise OverflowError("Trying to coerce negative values to unsigned integers")
 
     if is_integer_dtype(dtype) and (is_float_dtype(arr) or is_object_dtype(arr)):
         raise ValueError("Trying to coerce float values to integers")
diff --git a/pandas/core/generic.py b/pandas/core/generic.py
index f28f58b070368..a6cc2562bc8d6 100644
--- a/pandas/core/generic.py
+++ b/pandas/core/generic.py
@@ -6038,6 +6038,11 @@ def _convert(
         -------
         converted : same as input object
         """
+        validate_bool_kwarg(datetime, "datetime")
+        validate_bool_kwarg(numeric, "numeric")
+        validate_bool_kwarg(timedelta, "timedelta")
+        validate_bool_kwarg(coerce, "coerce")
+        validate_bool_kwarg(copy, "copy")
         return self._constructor(
             self._data.convert(
                 datetime=datetime,

From bb7cb11509b1d4a613a7b31994a57729a84ede38 Mon Sep 17 00:00:00 2001
From: jbrockmendel <jbrockmendel@gmail.com>
Date: Wed, 17 Jul 2019 17:40:05 -0700
Subject: [PATCH 02/10] simplify rarely-used maybe_convert_objects,
 soft_convert_objects, Block.convert

---
 pandas/core/dtypes/cast.py                    | 21 +++++++------------
 pandas/core/internals/blocks.py               | 19 ++++++-----------
 .../tests/dtypes/cast/test_convert_objects.py |  7 +++----
 pandas/tests/internals/test_internals.py      |  4 ----
 4 files changed, 16 insertions(+), 35 deletions(-)

diff --git a/pandas/core/dtypes/cast.py b/pandas/core/dtypes/cast.py
index f4f0f34764272..c91ad0cec406c 100644
--- a/pandas/core/dtypes/cast.py
+++ b/pandas/core/dtypes/cast.py
@@ -740,25 +740,18 @@ def astype_nansafe(arr, dtype, copy=True, skipna=False):
     return arr.view(dtype)
 
 
-def maybe_convert_objects(
-    values: np.ndarray,
-    convert_dates: bool = True,
-    convert_numeric: bool = True,
-    convert_timedeltas: bool = True,
-    copy: bool = True,
-):
+def maybe_convert_objects(values: np.ndarray, convert_numeric: bool = True):
     """ if we have an object dtype, try to coerce dates and/or numbers """
-    validate_bool_kwarg(convert_dates, "convert_dates")
     validate_bool_kwarg(convert_numeric, "convert_numeric")
-    validate_bool_kwarg(convert_timedeltas, "convert_timedeltas")
-    validate_bool_kwarg(copy, "copy")
+
+    orig_values = values
 
     # convert dates
-    if convert_dates and values.dtype == np.object_:
+    if values.dtype == np.object_:
         values = lib.maybe_convert_objects(values, convert_datetime=True)
 
     # convert timedeltas
-    if convert_timedeltas and values.dtype == np.object_:
+    if values.dtype == np.object_:
         values = lib.maybe_convert_objects(values, convert_timedelta=True)
 
     # convert to numeric
@@ -779,7 +772,8 @@ def maybe_convert_objects(
             # soft-conversion
             values = lib.maybe_convert_objects(values)
 
-    values = values.copy() if copy else values
+    if values is orig_values:
+        values = values.copy()
 
     return values
 
@@ -799,7 +793,6 @@ def soft_convert_objects(
     validate_bool_kwarg(timedelta, "timedelta")
     validate_bool_kwarg(coerce, "coerce")
     validate_bool_kwarg(copy, "copy")
-    assert not coerce  # we're only called from one place in internals.blocks
 
     conversion_count = sum((datetime, numeric, timedelta))
     if conversion_count == 0:
diff --git a/pandas/core/internals/blocks.py b/pandas/core/internals/blocks.py
index 26aca34f20594..7250bc8af4c3b 100644
--- a/pandas/core/internals/blocks.py
+++ b/pandas/core/internals/blocks.py
@@ -18,7 +18,6 @@
     find_common_type,
     infer_dtype_from,
     infer_dtype_from_scalar,
-    maybe_convert_objects,
     maybe_downcast_to_dtype,
     maybe_infer_dtype_type,
     maybe_promote,
@@ -2789,27 +2788,21 @@ def convert(self, *args, **kwargs):
 
         if args:
             raise NotImplementedError
-        by_item = kwargs.get("by_item", True)
+        by_item = kwargs.pop("by_item", True)
 
         new_inputs = ["coerce", "datetime", "numeric", "timedelta"]
-        new_style = False
-        for kw in new_inputs:
-            new_style |= kw in kwargs
 
-        if new_style:
-            fn = soft_convert_objects
-            fn_inputs = new_inputs
-        else:
-            fn = maybe_convert_objects
-            fn_inputs = ["convert_dates", "convert_numeric", "convert_timedeltas"]
+        fn_inputs = new_inputs
         fn_inputs += ["copy"]
 
-        fn_kwargs = {key: kwargs[key] for key in fn_inputs if key in kwargs}
+        fn_kwargs = {key: kwargs.pop(key) for key in fn_inputs if key in kwargs}
+        if kwargs:
+            raise ValueError("Unrecognized keywords: {kwargs}".format(kwargs=kwargs))
 
         # operate column-by-column
         def f(m, v, i):
             shape = v.shape
-            values = fn(v.ravel(), **fn_kwargs)
+            values = soft_convert_objects(v.ravel(), **fn_kwargs)
             if isinstance(values, np.ndarray):
                 # TODO: allow EA once reshape is supported
                 values = values.reshape(shape)
diff --git a/pandas/tests/dtypes/cast/test_convert_objects.py b/pandas/tests/dtypes/cast/test_convert_objects.py
index 45980dbd82736..a28d554acd312 100644
--- a/pandas/tests/dtypes/cast/test_convert_objects.py
+++ b/pandas/tests/dtypes/cast/test_convert_objects.py
@@ -5,9 +5,8 @@
 
 
 @pytest.mark.parametrize("data", [[1, 2], ["apply", "banana"]])
-@pytest.mark.parametrize("copy", [True, False])
-def test_maybe_convert_objects_copy(data, copy):
+def test_maybe_convert_objects_copy(data):
     arr = np.array(data)
-    out = maybe_convert_objects(arr, copy=copy)
+    out = maybe_convert_objects(arr)
 
-    assert (arr is out) is (not copy)
+    assert arr is not out
diff --git a/pandas/tests/internals/test_internals.py b/pandas/tests/internals/test_internals.py
index 655e484bc34d1..b56251aae884e 100644
--- a/pandas/tests/internals/test_internals.py
+++ b/pandas/tests/internals/test_internals.py
@@ -584,10 +584,6 @@ def _compare(old_mgr, new_mgr):
         new_mgr = mgr.convert()
         _compare(mgr, new_mgr)
 
-        mgr = create_mgr("a, b: object; f: i8; g: f8")
-        new_mgr = mgr.convert()
-        _compare(mgr, new_mgr)
-
         # convert
         mgr = create_mgr("a,b,foo: object; f: i8; g: f8")
         mgr.set("a", np.array(["1"] * N, dtype=np.object_))

From 6f28f0b970852ee9c16a49c69fd6ba589847d337 Mon Sep 17 00:00:00 2001
From: jbrockmendel <jbrockmendel@gmail.com>
Date: Wed, 17 Jul 2019 18:10:30 -0700
Subject: [PATCH 03/10] cleanup

---
 pandas/core/internals/blocks.py | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/pandas/core/internals/blocks.py b/pandas/core/internals/blocks.py
index 7250bc8af4c3b..bc28cfe15d152 100644
--- a/pandas/core/internals/blocks.py
+++ b/pandas/core/internals/blocks.py
@@ -2779,21 +2779,15 @@ def is_bool(self):
         return lib.is_bool_array(self.values.ravel())
 
     # TODO: Refactor when convert_objects is removed since there will be 1 path
-    def convert(self, *args, **kwargs):
+    def convert(self, **kwargs):
         """ attempt to coerce any object types to better types return a copy of
         the block (if copy = True) by definition we ARE an ObjectBlock!!!!!
 
         can return multiple blocks!
         """
-
-        if args:
-            raise NotImplementedError
         by_item = kwargs.pop("by_item", True)
 
-        new_inputs = ["coerce", "datetime", "numeric", "timedelta"]
-
-        fn_inputs = new_inputs
-        fn_inputs += ["copy"]
+        fn_inputs = ["coerce", "datetime", "numeric", "timedelta", "copy"]
 
         fn_kwargs = {key: kwargs.pop(key) for key in fn_inputs if key in kwargs}
         if kwargs:

From c0be483797859bbca490bf0540c920d6f8b127fc Mon Sep 17 00:00:00 2001
From: jbrockmendel <jbrockmendel@gmail.com>
Date: Wed, 17 Jul 2019 18:25:52 -0700
Subject: [PATCH 04/10] make kwargs explicit

---
 pandas/core/internals/blocks.py | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/pandas/core/internals/blocks.py b/pandas/core/internals/blocks.py
index bc28cfe15d152..2480efa6ad548 100644
--- a/pandas/core/internals/blocks.py
+++ b/pandas/core/internals/blocks.py
@@ -2779,24 +2779,32 @@ def is_bool(self):
         return lib.is_bool_array(self.values.ravel())
 
     # TODO: Refactor when convert_objects is removed since there will be 1 path
-    def convert(self, **kwargs):
+    def convert(
+        self,
+        by_item: bool = True,
+        datetime: bool = True,
+        numeric: bool = True,
+        timedelta: bool = True,
+        coerce: bool = False,
+        copy: bool = True,
+    ):
         """ attempt to coerce any object types to better types return a copy of
         the block (if copy = True) by definition we ARE an ObjectBlock!!!!!
 
         can return multiple blocks!
         """
-        by_item = kwargs.pop("by_item", True)
-
-        fn_inputs = ["coerce", "datetime", "numeric", "timedelta", "copy"]
-
-        fn_kwargs = {key: kwargs.pop(key) for key in fn_inputs if key in kwargs}
-        if kwargs:
-            raise ValueError("Unrecognized keywords: {kwargs}".format(kwargs=kwargs))
 
         # operate column-by-column
         def f(m, v, i):
             shape = v.shape
-            values = soft_convert_objects(v.ravel(), **fn_kwargs)
+            values = soft_convert_objects(
+                v.ravel(),
+                datetime=datetime,
+                numeric=numeric,
+                timedelta=timedelta,
+                coerce=coerce,
+                copy=copy,
+            )
             if isinstance(values, np.ndarray):
                 # TODO: allow EA once reshape is supported
                 values = values.reshape(shape)
@@ -2804,7 +2812,7 @@ def f(m, v, i):
             values = _block_shape(values, ndim=self.ndim)
             return values
 
-        if by_item and not self._is_single_block:
+        if by_item and self.ndim == 2:
             blocks = self.split_and_operate(None, f, False)
         else:
             values = f(None, self.values.ravel(), None)

From dc3d1a1cc86ec3087b97f2f4d35b9a4910636c19 Mon Sep 17 00:00:00 2001
From: jbrockmendel <jbrockmendel@gmail.com>
Date: Wed, 17 Jul 2019 19:43:07 -0700
Subject: [PATCH 05/10] remove by_item kwarg

---
 pandas/core/internals/blocks.py   | 9 ++++-----
 pandas/core/internals/managers.py | 1 -
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/pandas/core/internals/blocks.py b/pandas/core/internals/blocks.py
index 2480efa6ad548..643423ce0cb32 100644
--- a/pandas/core/internals/blocks.py
+++ b/pandas/core/internals/blocks.py
@@ -827,7 +827,7 @@ def replace(
             )
         if convert:
             blocks = [
-                b.convert(by_item=True, numeric=False, copy=not inplace) for b in blocks
+                b.convert(numeric=False, copy=not inplace) for b in blocks
             ]
         return blocks
 
@@ -2781,7 +2781,6 @@ def is_bool(self):
     # TODO: Refactor when convert_objects is removed since there will be 1 path
     def convert(
         self,
-        by_item: bool = True,
         datetime: bool = True,
         numeric: bool = True,
         timedelta: bool = True,
@@ -2812,7 +2811,7 @@ def f(m, v, i):
             values = _block_shape(values, ndim=self.ndim)
             return values
 
-        if by_item and self.ndim == 2:
+        if self.ndim == 2:
             blocks = self.split_and_operate(None, f, False)
         else:
             values = f(None, self.values.ravel(), None)
@@ -3036,7 +3035,7 @@ def re_replacer(s):
         # convert
         block = self.make_block(new_values)
         if convert:
-            block = block.convert(by_item=True, numeric=False)
+            block = block.convert(numeric=False)
         return block
 
     def _replace_coerce(
@@ -3076,7 +3075,7 @@ def _replace_coerce(
             )
             if convert:
                 block = [
-                    b.convert(by_item=True, numeric=False, copy=True) for b in block
+                    b.convert(numeric=False, copy=True) for b in block
                 ]
             return block
         return self
diff --git a/pandas/core/internals/managers.py b/pandas/core/internals/managers.py
index 2e7280eeae0e2..394c0773409f2 100644
--- a/pandas/core/internals/managers.py
+++ b/pandas/core/internals/managers.py
@@ -1551,7 +1551,6 @@ def index(self):
 
     def convert(self, **kwargs):
         """ convert the whole block as one """
-        kwargs["by_item"] = False
         return self.apply("convert", **kwargs)
 
     @property

From 37942b16455918e6d41244ca4a0457de3bb7f18d Mon Sep 17 00:00:00 2001
From: jbrockmendel <jbrockmendel@gmail.com>
Date: Thu, 18 Jul 2019 07:42:56 -0700
Subject: [PATCH 06/10] blackify

---
 pandas/core/internals/blocks.py | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/pandas/core/internals/blocks.py b/pandas/core/internals/blocks.py
index 643423ce0cb32..bc83c9c5950ec 100644
--- a/pandas/core/internals/blocks.py
+++ b/pandas/core/internals/blocks.py
@@ -826,9 +826,7 @@ def replace(
                 convert=convert,
             )
         if convert:
-            blocks = [
-                b.convert(numeric=False, copy=not inplace) for b in blocks
-            ]
+            blocks = [b.convert(numeric=False, copy=not inplace) for b in blocks]
         return blocks
 
     def _replace_single(self, *args, **kwargs):
@@ -3074,9 +3072,7 @@ def _replace_coerce(
                 mask=mask,
             )
             if convert:
-                block = [
-                    b.convert(numeric=False, copy=True) for b in block
-                ]
+                block = [b.convert(numeric=False, copy=True) for b in block]
             return block
         return self
 

From 7137e98d03c202efdd35d44382bf802cb3d93ba5 Mon Sep 17 00:00:00 2001
From: jbrockmendel <jbrockmendel@gmail.com>
Date: Thu, 18 Jul 2019 10:19:24 -0700
Subject: [PATCH 07/10] mypy fixup

---
 pandas/core/internals/blocks.py | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/pandas/core/internals/blocks.py b/pandas/core/internals/blocks.py
index bc83c9c5950ec..3449cfee488e2 100644
--- a/pandas/core/internals/blocks.py
+++ b/pandas/core/internals/blocks.py
@@ -668,7 +668,14 @@ def _astype(self, dtype, copy=False, errors="raise", values=None, **kwargs):
                 )
         return newb
 
-    def convert(self, copy=True, **kwargs):
+    def convert(
+        self,
+        copy: bool = True,
+        datetime: bool = True,
+        numeric: bool = True,
+        timedelta: bool = True,
+        coerce: bool = False,
+    ):
         """ attempt to coerce any object types to better types return a copy
         of the block (if copy = True) by definition we are not an ObjectBlock
         here!
@@ -2779,11 +2786,11 @@ def is_bool(self):
     # TODO: Refactor when convert_objects is removed since there will be 1 path
     def convert(
         self,
+        copy: bool = True,
         datetime: bool = True,
         numeric: bool = True,
         timedelta: bool = True,
         coerce: bool = False,
-        copy: bool = True,
     ):
         """ attempt to coerce any object types to better types return a copy of
         the block (if copy = True) by definition we ARE an ObjectBlock!!!!!

From b17489aa1d5b1256f97c88425e45b7e179083237 Mon Sep 17 00:00:00 2001
From: jbrockmendel <jbrockmendel@gmail.com>
Date: Sat, 20 Jul 2019 12:52:10 -0700
Subject: [PATCH 08/10] docstring, use is_object_dtype

---
 pandas/core/dtypes/cast.py | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/pandas/core/dtypes/cast.py b/pandas/core/dtypes/cast.py
index 7b343cd2b0c28..fd8536e38eee7 100644
--- a/pandas/core/dtypes/cast.py
+++ b/pandas/core/dtypes/cast.py
@@ -729,21 +729,32 @@ def astype_nansafe(arr, dtype, copy=True, skipna=False):
 
 
 def maybe_convert_objects(values: np.ndarray, convert_numeric: bool = True):
-    """ if we have an object dtype, try to coerce dates and/or numbers """
+    """
+    If we have an object dtype array, try to coerce dates and/or numbers.
+
+    Parameters
+    ----------
+    values : ndarray
+    convert_numeric : bool, default True
+
+    Returns
+    -------
+    ndarray or DatetimeIndex
+    """
     validate_bool_kwarg(convert_numeric, "convert_numeric")
 
     orig_values = values
 
     # convert dates
-    if values.dtype == np.object_:
+    if is_object_dtype(values.dtype):
         values = lib.maybe_convert_objects(values, convert_datetime=True)
 
     # convert timedeltas
-    if values.dtype == np.object_:
+    if is_object_dtype(values.dtype):
         values = lib.maybe_convert_objects(values, convert_timedelta=True)
 
     # convert to numeric
-    if values.dtype == np.object_:
+    if is_object_dtype(values.dtype):
         if convert_numeric:
             try:
                 new_values = lib.maybe_convert_numeric(

From 2e3eb9d99be1e03cb501373998c03a2e0ccf236f Mon Sep 17 00:00:00 2001
From: jbrockmendel <jbrockmendel@gmail.com>
Date: Sat, 20 Jul 2019 13:22:56 -0700
Subject: [PATCH 09/10] Merge branch 'master' of
 https://github.com/pandas-dev/pandas into convert_objects


From b32f6521b8c9c802049c88d3868eb532954c60d0 Mon Sep 17 00:00:00 2001
From: jbrockmendel <jbrockmendel@gmail.com>
Date: Sat, 20 Jul 2019 13:23:19 -0700
Subject: [PATCH 10/10] remove comment

---
 pandas/core/internals/blocks.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/pandas/core/internals/blocks.py b/pandas/core/internals/blocks.py
index 3449cfee488e2..ace57938f948c 100644
--- a/pandas/core/internals/blocks.py
+++ b/pandas/core/internals/blocks.py
@@ -2783,7 +2783,6 @@ def is_bool(self):
         """
         return lib.is_bool_array(self.values.ravel())
 
-    # TODO: Refactor when convert_objects is removed since there will be 1 path
     def convert(
         self,
         copy: bool = True,