create helper function for converting datetime string from API descriptions into datetime

[jreiberkyle]

Support usage of the API description datetime information, provided as an RFC 3339 string, by creating a helper function for converting that string into a datetime object.

e.g. something like: add to io.py

from datetime import datetime

DATE_FORMAT = "%Y-%m-%dT%H:%M:%S.%fZ"

def to_datetime(rfc3339: str) -> datetime:
    """Convert an RFC 3339 string from an API response to a datetime."""
    return datetime.strptime(rfc3339, DATE_FORMAT)

add to test_io.py

from datetime import datetime

@pytest.mark.parametrize(
    "rfc3339, expected",
    [("2021-02-03T01:40:07.359Z", datetime(2021, 2, 3, 1, 40, 7, 359000)), ... ])
def test_to_datetime(rfc3339, expected):
    assert io.to_datetime(rfc3339) == expected