Skip to content

API: Datetime/TimedeltaArray from to_datetime #24660

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Jan 8, 2019
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
35 changes: 33 additions & 2 deletions pandas/core/arrays/array_.py
Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
from pandas._libs import lib, tslibs

from pandas.core.dtypes.common import is_extension_array_dtype
from pandas.core.dtypes.common import (
is_datetime64_ns_dtype, is_extension_array_dtype, is_timedelta64_ns_dtype)
from pandas.core.dtypes.dtypes import registry

from pandas import compat
Expand Down Expand Up @@ -75,9 +76,10 @@ def array(data, # type: Sequence[object]
See Also
--------
numpy.array : Construct a NumPy array.
arrays.PandasArray : ExtensionArray wrapping a NumPy array.
Series : Construct a pandas Series.
Index : Construct a pandas Index.
arrays.PandasArray : ExtensionArray wrapping a NumPy array.
Series.array : Extract the array stored within a Series.

Notes
-----
Expand Down Expand Up @@ -120,6 +122,26 @@ def array(data, # type: Sequence[object]
['a', 'b']
Length: 2, dtype: str32

Finally, Pandas has arrays that mostly overlap with NumPy

* :class:`arrays.DatetimeArray`
* :class:`arrays.TimedeltaArray`

When data with a ``datetime64[ns]`` or ``timedelta64[ns]`` dtype is
passed, pandas will always return a ``DatetimeArray`` or ``TimedeltaArray``
rather than a ``PandasArray``. This is for symmetry with the case of
timezone-aware data, which NumPy does not natively support.

>>> pd.array(['2015', '2016'], dtype='datetime64[ns]')
<DatetimeArray>
['2015-01-01 00:00:00', '2016-01-01 00:00:00']
Length: 2, dtype: datetime64[ns]

>>> pd.array(["1H", "2H"], dtype='timedelta64[ns]')
<TimedeltaArray>
['01:00:00', '02:00:00']
Length: 2, dtype: timedelta64[ns]

Examples
--------
If a dtype is not specified, `data` is passed through to
Expand Down Expand Up @@ -239,5 +261,14 @@ def array(data, # type: Sequence[object]

# TODO(BooleanArray): handle this type

# Pandas overrides NumPy for
# 1. datetime64[ns]
# 2. timedelta64[ns]
# so that a DatetimeArray is returned.
if is_datetime64_ns_dtype(dtype):
return DatetimeArray._from_sequence(data, dtype=dtype, copy=copy)
elif is_timedelta64_ns_dtype(dtype):
return TimedeltaArray._from_sequence(data, dtype=dtype, copy=copy)

result = PandasArray._from_sequence(data, dtype=dtype, copy=copy)
return result
32 changes: 30 additions & 2 deletions pandas/tests/arrays/test_array.py
Original file line number Diff line number Diff line change
Expand Up @@ -36,8 +36,36 @@

# Datetime (naive)
([1, 2], np.dtype('datetime64[ns]'),
PandasArray(np.array([1, 2], dtype='datetime64[ns]'))),
# TODO(DatetimeArray): add here
pd.arrays.DatetimeArray._from_sequence(
np.array([1, 2], dtype='datetime64[ns]'))),

(np.array([1, 2], dtype='datetime64[ns]'), None,
pd.arrays.DatetimeArray._from_sequence(
np.array([1, 2], dtype='datetime64[ns]'))),

(pd.DatetimeIndex(['2000', '2001']), np.dtype('datetime64[ns]'),
pd.arrays.DatetimeArray._from_sequence(['2000', '2001'])),

(pd.DatetimeIndex(['2000', '2001']), None,
pd.arrays.DatetimeArray._from_sequence(['2000', '2001'])),

(['2000', '2001'], np.dtype('datetime64[ns]'),
pd.arrays.DatetimeArray._from_sequence(['2000', '2001'])),

# Datetime (tz-aware)
(['2000', '2001'], pd.DatetimeTZDtype(tz="CET"),
pd.arrays.DatetimeArray._from_sequence(
['2000', '2001'], dtype=pd.DatetimeTZDtype(tz="CET"))),

# Timedelta
(['1H', '2H'], np.dtype('timedelta64[ns]'),
pd.arrays.TimedeltaArray._from_sequence(['1H', '2H'])),

(pd.TimedeltaIndex(['1H', '2H']), np.dtype('timedelta64[ns]'),
pd.arrays.TimedeltaArray._from_sequence(['1H', '2H'])),

(pd.TimedeltaIndex(['1H', '2H']), None,
pd.arrays.TimedeltaArray._from_sequence(['1H', '2H'])),

# Category
(['a', 'b'], 'category', pd.Categorical(['a', 'b'])),
Expand Down
14 changes: 14 additions & 0 deletions pandas/tests/series/test_internals.py
Original file line number Diff line number Diff line change
Expand Up @@ -313,6 +313,20 @@ def test_constructor_no_pandas_array(self):
tm.assert_series_equal(ser, result)
assert isinstance(result._data.blocks[0], IntBlock)

def test_from_array(self):
result = pd.Series(pd.array(['1H', '2H'], dtype='timedelta64[ns]'))
assert result._data.blocks[0].is_extension is False

result = pd.Series(pd.array(['2015'], dtype='datetime64[ns]'))
assert result._data.blocks[0].is_extension is False

def test_from_list_dtype(self):
result = pd.Series(['1H', '2H'], dtype='timedelta64[ns]')
assert result._data.blocks[0].is_extension is False

result = pd.Series(['2015'], dtype='datetime64[ns]')
assert result._data.blocks[0].is_extension is False


def test_hasnans_unchached_for_series():
# GH#19700
Expand Down