strptime does not handle nanoseconds for

[gongy]

Using DateTime64(9, 'UTC') - the python parser is not able to translate the 9 digits of precision. The error is

  File "aiochclient/_types.pyx", line 29, in aiochclient._types._datetime_parse_f
  File "/usr/lib/python3.9/_strptime.py", line 568, in _strptime_datetime
    tt, fraction, gmtoff_fraction = _strptime(data_string, format)
  File "/usr/lib/python3.9/_strptime.py", line 352, in _strptime
    raise ValueError("unconverted data remains: %s" %
ValueError: unconverted data remains: 64

For some reason it only happens on Python 3.9. Happy to patch this if you have opinion/direction.

[cxong]

FWIW one workaround is to convert to unix nanoseconds (i.e. select toUnixTimestamp64Nano(ts)) and convert the result back to the appropriate type afterwards (e.g. numpy or pandas datetime types). Python's native datetime type does not support nanoseconds.