`numpy:datetime_as_string`

Signature

def datetime_as_string(arr, unit = None, timezone = naive, casting = same_kind)

Summary

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

import numpy as np
from zoneinfo import ZoneInfo
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 ``ZoneInfo`` object will print the appropriate offset

np.datetime_as_string(d, timezone=ZoneInfo('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')

'casting' can be used to specify whether precision can be changed

np.datetime_as_string(d, unit='h', casting='safe')

✗

Traceback (most recent call last):
  File "<doctest numpy:datetime_as_string[0]>", line 1, in <module>
    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'

Aliases

numpy.datetime_as_string