numpy.datetime_as_string¶
-
numpy.
datetime_as_string
(arr, unit=None, timezone='naive', casting='same_kind')¶ Convert an array of datetimes into an array of strings.
Parameters: arr : array_like of datetime64
The array of UTC timestamps to format.
unit : str
One of None, ‘auto’, or a datetime unit.
timezone : {‘naive’, ‘UTC’, ‘local’} or tzinfo
Timezone information to use when displaying the datetime. If ‘UTC’, end with a Z to indicate UTC time. If ‘local’, convert to the local timezone first, and suffix with a +-#### timezone offset. If a tzinfo object, then do as with ‘local’, but use the specified timezone.
casting : {‘no’, ‘equiv’, ‘safe’, ‘same_kind’, ‘unsafe’}
Casting to allow when changing between datetime units.
Returns: str_arr : ndarray
An array of strings the same shape as arr.
Examples
>>> d = np.arange('2002-10-27T04:30', 4*60, 60, dtype='M8[m]') >>> d array(['2002-10-27T04:30', '2002-10-27T05:30', '2002-10-27T06:30', '2002-10-27T07:30'], dtype='datetime64[m]')
Setting the timezone to UTC shows the same information, but with a Z suffix
>>> np.datetime_as_string(d, timezone='UTC') array(['2002-10-27T04:30Z', '2002-10-27T05:30Z', '2002-10-27T06:30Z', '2002-10-27T07:30Z'], dtype='<U35')
Note that we picked datetimes that cross a DST boundary. Passing in a
pytz
timezone object will print the appropriate offset:>>> np.datetime_as_string(d, timezone=pytz.timezone('US/Eastern'))
- array([‘2002-10-27T00:30-0400’, ‘2002-10-27T01:30-0400’,
- ‘2002-10-27T01:30-0500’, ‘2002-10-27T02:30-0500’], dtype=’<U39’)
Passing in a unit will change the precision:
>>> np.datetime_as_string(d, unit='h')
- array([‘2002-10-27T04’, ‘2002-10-27T05’, ‘2002-10-27T06’, ‘2002-10-27T07’],
- dtype=’<U32’)
>>> np.datetime_as_string(d, unit='s') array(['2002-10-27T04:30:00', '2002-10-27T05:30:00', '2002-10-27T06:30:00', '2002-10-27T07:30:00'], dtype='<U38')
But can be made to not lose precision:
>>> np.datetime_as_string(d, unit='h', casting='safe')
TypeError: Cannot create a datetime string as units ‘h’ from a NumPy datetime with units ‘m’ according to the rule ‘safe’