num2pydate loses millisecond information

[jackvreeken]

In 1.1.0 the num2pydate was added, as num2date no longer return a real_datetime. This change was rather annoying for me, as I was relying on the datetime'ish properties of real_datetime (e.g. being an instance of it). But as far as the bug is concerned:

One of my dates is 1970-01-01 02:00:00 and 13 milliseconds.

• When reading it with num2date in 1.0.4.2 I would get a Python datetime-ish (real_datetime) object with the right value.
• When reading it with num2date in 1.1.0 I would get a non-Python datetime object with the right value (a cftime.DatetimeGregorian instance I think).
• When reading it with num2pydate in 1.1.0 I would get a Python datetime "1970-01-01 02:00:00", with the milliseconds information lost.

[jswhit]

Can you be more specific about what you mean by the 'millisecond information is lost'?

Sorry this changed caused you grief.

[jackvreeken]

On second look, it seems to be related to parsing of arrays. I remember seeing an issue about this somewhere...

import pprint

from cftime import num2date, num2pydate

time_calendar = 'gregorian'
time_unit = 'hours since 1970-01-01 00:00:00.0 +0000'
time_values = [0.0, 1.0, 2.0, 3.0, 4.0]

# Wrong?
pprint.pprint(num2date(time_values, units=time_unit, calendar=time_calendar))  
# Correct?
pprint.pprint(num2pydate(time_values, units=time_unit, calendar=time_calendar))
# Correct?
pprint.pprint(num2date(time_values[2:3], units=time_unit, calendar=time_calendar))

Output:

array([cftime.DatetimeGregorian(1970-01-01 00:00:00),
       cftime.DatetimeGregorian(1970-01-01 01:00:00),
       cftime.DatetimeGregorian(1970-01-01 02:00:00.13),
       cftime.DatetimeGregorian(1970-01-01 03:00:00),
       cftime.DatetimeGregorian(1970-01-01 04:00:00)], dtype=object)
array([datetime.datetime(1970, 1, 1, 0, 0),
       datetime.datetime(1970, 1, 1, 1, 0),
       datetime.datetime(1970, 1, 1, 2, 0),
       datetime.datetime(1970, 1, 1, 3, 0),
       datetime.datetime(1970, 1, 1, 4, 0)], dtype=object)
array([cftime.DatetimeGregorian(1970-01-01 02:00:00)], dtype=object)

[jswhit]

This has been fixed by PR #146