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| author | Jonathan Reichelt Gjertsen <jonath.re@gmail.com> | 2021-10-01 19:55:10 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-10-01 14:55:10 -0300 |
| commit | 6ad932c41281a6b7e525aba8a1057c09065251fa (patch) | |
| tree | 94aa88060ea2aae84bd218781ac20881736130a1 | |
| parent | c7832859666971f4509847ddb2db0a0470c77e95 (diff) | |
| download | numpy-6ad932c41281a6b7e525aba8a1057c09065251fa.tar.gz | |
DOC: add example showing how to convert POSIX timestamps to datetime64 (#18984)
* DOC: add example showing how to convert POSIX timestamps to datetime64
Co-authored-by: Melissa Weber Mendonça <melissawm@gmail.com>
| -rw-r--r-- | doc/source/reference/arrays.datetime.rst | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/doc/source/reference/arrays.datetime.rst b/doc/source/reference/arrays.datetime.rst index e3b8d270d..63c93821b 100644 --- a/doc/source/reference/arrays.datetime.rst +++ b/doc/source/reference/arrays.datetime.rst @@ -25,7 +25,7 @@ form of the string, and can be either a :ref:`date unit <arrays.dtypes.dateunits :ref:`time unit <arrays.dtypes.timeunits>`. The date units are years ('Y'), months ('M'), weeks ('W'), and days ('D'), while the time units are hours ('h'), minutes ('m'), seconds ('s'), milliseconds ('ms'), and -some additional SI-prefix seconds-based units. The datetime64 data type +some additional SI-prefix seconds-based units. The datetime64 data type also accepts the string "NAT", in any combination of lowercase/uppercase letters, for a "Not A Time" value. @@ -74,6 +74,18 @@ datetime type with generic units. array(['2001-01-01T12:00:00.000', '2002-02-03T13:56:03.172'], dtype='datetime64[ms]') +An array of datetimes can be constructed from integers representing +POSIX timestamps with the given unit. + +.. admonition:: Example + + >>> np.array([0, 1577836800], dtype='datetime64[s]') + array(['1970-01-01T00:00:00', '2020-01-01T00:00:00'], + dtype='datetime64[s]') + + >>> np.array([0, 1577836800000]).astype('datetime64[ms]') + array(['1970-01-01T00:00:00.000', '2020-01-01T00:00:00.000'], + dtype='datetime64[ms]') The datetime type works with many common NumPy functions, for example :func:`arange` can be used to generate ranges of dates. @@ -120,9 +132,9 @@ Datetime and Timedelta Arithmetic NumPy allows the subtraction of two Datetime values, an operation which produces a number with a time unit. Because NumPy doesn't have a physical quantities system in its core, the timedelta64 data type was created -to complement datetime64. The arguments for timedelta64 are a number, +to complement datetime64. The arguments for timedelta64 are a number, to represent the number of units, and a date/time unit, such as -(D)ay, (M)onth, (Y)ear, (h)ours, (m)inutes, or (s)econds. The timedelta64 +(D)ay, (M)onth, (Y)ear, (h)ours, (m)inutes, or (s)econds. The timedelta64 data type also accepts the string "NAT" in place of the number for a "Not A Time" value. .. admonition:: Example |