Viewing file:  parser.py (3.48 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
import re
from datetime import datetime, timedelta, timezone
from pyrfc3339.utils import format_timezone
def parse(timestamp, utc=False, produce_naive=False):
"""
Parse an :RFC:`3339`-formatted timestamp and return a
:class:`datetime.datetime`.
If the timestamp is presented in UTC, then the `tzinfo` parameter of the
returned `datetime` will be set to :attr:`datetime.timezone.utc`.
>>> parse('2009-01-01T10:01:02Z')
datetime.datetime(2009, 1, 1, 10, 1, 2, tzinfo=datetime.timezone.utc)
Otherwise, a :class:`datetime.timezone` instance is created with the appropriate offset, and
the `tzinfo` parameter of the returned `datetime` is set to that value.
>>> parse('2009-01-01T14:01:02-04:00')
datetime.datetime(2009, 1, 1, 14, 1, 2, tzinfo=datetime.timezone(datetime.timedelta(days=-1, seconds=72000), '<UTC-04:00>'))
However, if `parse()` is called with `utc=True`, then the returned
`datetime` will be normalized to UTC (and its tzinfo parameter set to
`datetime.timezone.utc`), regardless of the input timezone.
>>> parse('2009-01-01T06:01:02-04:00', utc=True)
datetime.datetime(2009, 1, 1, 10, 1, 2, tzinfo=datetime.timezone.utc)
The input is strictly required to conform to :RFC:`3339`, and appropriate
exceptions are thrown for invalid input.
>>> parse('2009-01-01T06:01:02')
Traceback (most recent call last):
...
ValueError: timestamp does not conform to RFC 3339
>>> parse('2009-01-01T25:01:02Z')
Traceback (most recent call last):
...
ValueError: hour must be in 0..23
"""
parse_re = re.compile(
r"""^(?:(?:(?P<date_fullyear>[0-9]{4})\-(?P<date_month>[0-9]{2})\-(?P<date_mday>[0-9]{2}))T(?:(?:(?P<time_hour>[0-9]{2})\:(?P<time_minute>[0-9]{2})\:(?P<time_second>[0-9]{2})(?P<time_secfrac>(?:\.[0-9]{1,}))?)(?P<time_offset>(?:Z|(?P<time_numoffset>(?P<time_houroffset>(?:\+|\-)[0-9]{2})\:(?P<time_minuteoffset>[0-9]{2}))))))$""",
re.I | re.X,
)
match = parse_re.match(timestamp)
if match is not None:
if match.group("time_offset") in ["Z", "z", "+00:00", "-00:00"]:
if produce_naive is True:
tzinfo = None
else:
tzinfo = timezone.utc
else:
if produce_naive is True:
raise ValueError(
"cannot produce a naive datetime from a local timestamp"
)
else:
tz_hours = int(match.group("time_houroffset"))
tz_minutes = int(match.group("time_minuteoffset"))
if tz_hours < 0:
tz_minutes *= -1
td = timedelta(hours=tz_hours, minutes=tz_minutes)
tzinfo = timezone(td, f"<UTC{format_timezone(td.total_seconds())}>")
secfrac = match.group("time_secfrac")
if secfrac is None:
microsecond = 0
else:
microsecond = int(round(float(secfrac) * 1000000))
dt_out = datetime(
year=int(match.group("date_fullyear")),
month=int(match.group("date_month")),
day=int(match.group("date_mday")),
hour=int(match.group("time_hour")),
minute=int(match.group("time_minute")),
second=int(match.group("time_second")),
microsecond=microsecond,
tzinfo=tzinfo,
)
if utc:
dt_out = dt_out.astimezone(timezone.utc)
return dt_out
else:
raise ValueError("timestamp does not conform to RFC 3339")
|