def parse_datetime(
date_string: str,
from_dt: Optional[datetime.datetime] = None
) -> Optional[datetime.datetime]:
"""
Parses a string into a datetime.datetime object, using |from_dt| as a base
for any relative dates.
"""
if date_string == '' or date_string.isspace():
return None
if is_str_field_none(date_string):
return None
settings: Dict[str, Any] = {'PREFER_DAY_OF_MONTH': 'first'}
if from_dt:
settings['RELATIVE_BASE'] = from_dt
date_string = munge_date_string(date_string)
# Only special-case strings that start with a - (to avoid parsing regular
# timestamps like '2016-05-14') and that include non punctuation (to avoid
# ingested values like '--')
if date_string.startswith('-') and _has_non_punctuation(date_string):
parsed = parse_datetime_with_negative_component(date_string, settings)
else:
parsed = dateparser.parse(date_string,
languages=['en'],
settings=settings)
if parsed:
return parsed
raise ValueError("cannot parse date: %s" % date_string)
def parse_datetime(
date_string: str,
from_dt: Optional[datetime.datetime] = None
) -> Optional[datetime.datetime]:
"""
Parses a string into a datetime.datetime object, using |from_dt| as a base
for any relative dates.
"""
if (date_string == "" or date_string.isspace()
or _is_str_field_zeros(date_string)
or is_str_field_none(date_string)):
return None
if is_yyyymmdd_date(date_string):
as_date = parse_yyyymmdd_date(date_string)
if not as_date:
raise ValueError(
f"Parsed date for string [{date_string}] is unexpectedly None."
)
return datetime.datetime(year=as_date.year,
month=as_date.month,
day=as_date.day)
settings: Dict[str, Any] = {"PREFER_DAY_OF_MONTH": "first"}
if from_dt:
settings["RELATIVE_BASE"] = from_dt
date_string = munge_date_string(date_string)
# Only special-case strings that start with a - (to avoid parsing regular
# timestamps like '2016-05-14') and that include non punctuation (to avoid
# ingested values like '--')
if date_string.startswith("-") and _has_non_punctuation(date_string):
parsed = parse_datetime_with_negative_component(date_string, settings)
else:
parsed = dateparser.parse(date_string,
languages=["en"],
settings=settings)
if parsed:
return parsed
raise ValueError("cannot parse date: %s" % date_string)
def test_mungeDateString_ZeroAm():
assert munge_date_string('Jan 1, 2018 00:00 AM') == \
'Jan 1, 2018 12:00 AM'
def test_mungeDateString_noDay():
assert munge_date_string('4y 3m') == '4year 3month'
def test_mungeDateString_noMonth():
assert munge_date_string('9Y 28D') == '9year 28day'
def test_mungeDateString_noYear():
assert munge_date_string('10M 12D') == '10month 12day'
def test_mungeDateString_caseInsensitive():
assert munge_date_string('1Y 1M 1D') == '1year 1month 1day'
def test_mungeDateString_doesntMunge():
assert munge_date_string('1year 1month 1day') == '1year 1month 1day'
def test_mungeDateString_munges():
assert munge_date_string('1y 1m 1d') == '1year 1month 1day'
def test_mungeDateString_ZeroAm() -> None:
assert munge_date_string("Jan 1, 2018 00:00 AM") == "Jan 1, 2018 12:00 AM"
def test_mungeDateString_noDay() -> None:
assert munge_date_string("4y 3m") == "4year 3month"
def test_mungeDateString_noMonth() -> None:
assert munge_date_string("9Y 28D") == "9year 28day"
def test_mungeDateString_noYear() -> None:
assert munge_date_string("10M 12D") == "10month 12day"
def test_mungeDateString_caseInsensitive() -> None:
assert munge_date_string("1Y 1M 1D") == "1year 1month 1day"
def test_mungeDateString_doesntMunge() -> None:
assert munge_date_string("1year 1month 1day") == "1year 1month 1day"
def test_mungeDateString_munges() -> None:
assert munge_date_string("1y 1m 1d") == "1year 1month 1day"
