249 lines
7.5 KiB
Python
249 lines
7.5 KiB
Python
"""
|
|
Functions to parse datetime objects.
|
|
|
|
We're using regular expressions rather than time.strptime because:
|
|
- They provide both validation and parsing.
|
|
- They're more flexible for datetimes.
|
|
- The date/datetime/time constructors produce friendlier error messages.
|
|
|
|
Stolen from https://raw.githubusercontent.com/django/django/main/django/utils/dateparse.py at
|
|
9718fa2e8abe430c3526a9278dd976443d4ae3c6
|
|
|
|
Changed to:
|
|
* use standard python datetime types not django.utils.timezone
|
|
* raise ValueError when regex doesn't match rather than returning None
|
|
* support parsing unix timestamps for dates and datetimes
|
|
"""
|
|
import re
|
|
from datetime import date, datetime, time, timedelta, timezone
|
|
from typing import Dict, Optional, Type, Union
|
|
|
|
from pydantic.v1 import errors
|
|
|
|
date_expr = r'(?P<year>\d{4})-(?P<month>\d{1,2})-(?P<day>\d{1,2})'
|
|
time_expr = (
|
|
r'(?P<hour>\d{1,2}):(?P<minute>\d{1,2})'
|
|
r'(?::(?P<second>\d{1,2})(?:\.(?P<microsecond>\d{1,6})\d{0,6})?)?'
|
|
r'(?P<tzinfo>Z|[+-]\d{2}(?::?\d{2})?)?$'
|
|
)
|
|
|
|
date_re = re.compile(f'{date_expr}$')
|
|
time_re = re.compile(time_expr)
|
|
datetime_re = re.compile(f'{date_expr}[T ]{time_expr}')
|
|
|
|
standard_duration_re = re.compile(
|
|
r'^'
|
|
r'(?:(?P<days>-?\d+) (days?, )?)?'
|
|
r'((?:(?P<hours>-?\d+):)(?=\d+:\d+))?'
|
|
r'(?:(?P<minutes>-?\d+):)?'
|
|
r'(?P<seconds>-?\d+)'
|
|
r'(?:\.(?P<microseconds>\d{1,6})\d{0,6})?'
|
|
r'$'
|
|
)
|
|
|
|
# Support the sections of ISO 8601 date representation that are accepted by timedelta
|
|
iso8601_duration_re = re.compile(
|
|
r'^(?P<sign>[-+]?)'
|
|
r'P'
|
|
r'(?:(?P<days>\d+(.\d+)?)D)?'
|
|
r'(?:T'
|
|
r'(?:(?P<hours>\d+(.\d+)?)H)?'
|
|
r'(?:(?P<minutes>\d+(.\d+)?)M)?'
|
|
r'(?:(?P<seconds>\d+(.\d+)?)S)?'
|
|
r')?'
|
|
r'$'
|
|
)
|
|
|
|
EPOCH = datetime(1970, 1, 1)
|
|
# if greater than this, the number is in ms, if less than or equal it's in seconds
|
|
# (in seconds this is 11th October 2603, in ms it's 20th August 1970)
|
|
MS_WATERSHED = int(2e10)
|
|
# slightly more than datetime.max in ns - (datetime.max - EPOCH).total_seconds() * 1e9
|
|
MAX_NUMBER = int(3e20)
|
|
StrBytesIntFloat = Union[str, bytes, int, float]
|
|
|
|
|
|
def get_numeric(value: StrBytesIntFloat, native_expected_type: str) -> Union[None, int, float]:
|
|
if isinstance(value, (int, float)):
|
|
return value
|
|
try:
|
|
return float(value)
|
|
except ValueError:
|
|
return None
|
|
except TypeError:
|
|
raise TypeError(f'invalid type; expected {native_expected_type}, string, bytes, int or float')
|
|
|
|
|
|
def from_unix_seconds(seconds: Union[int, float]) -> datetime:
|
|
if seconds > MAX_NUMBER:
|
|
return datetime.max
|
|
elif seconds < -MAX_NUMBER:
|
|
return datetime.min
|
|
|
|
while abs(seconds) > MS_WATERSHED:
|
|
seconds /= 1000
|
|
dt = EPOCH + timedelta(seconds=seconds)
|
|
return dt.replace(tzinfo=timezone.utc)
|
|
|
|
|
|
def _parse_timezone(value: Optional[str], error: Type[Exception]) -> Union[None, int, timezone]:
|
|
if value == 'Z':
|
|
return timezone.utc
|
|
elif value is not None:
|
|
offset_mins = int(value[-2:]) if len(value) > 3 else 0
|
|
offset = 60 * int(value[1:3]) + offset_mins
|
|
if value[0] == '-':
|
|
offset = -offset
|
|
try:
|
|
return timezone(timedelta(minutes=offset))
|
|
except ValueError:
|
|
raise error()
|
|
else:
|
|
return None
|
|
|
|
|
|
def parse_date(value: Union[date, StrBytesIntFloat]) -> date:
|
|
"""
|
|
Parse a date/int/float/string and return a datetime.date.
|
|
|
|
Raise ValueError if the input is well formatted but not a valid date.
|
|
Raise ValueError if the input isn't well formatted.
|
|
"""
|
|
if isinstance(value, date):
|
|
if isinstance(value, datetime):
|
|
return value.date()
|
|
else:
|
|
return value
|
|
|
|
number = get_numeric(value, 'date')
|
|
if number is not None:
|
|
return from_unix_seconds(number).date()
|
|
|
|
if isinstance(value, bytes):
|
|
value = value.decode()
|
|
|
|
match = date_re.match(value) # type: ignore
|
|
if match is None:
|
|
raise errors.DateError()
|
|
|
|
kw = {k: int(v) for k, v in match.groupdict().items()}
|
|
|
|
try:
|
|
return date(**kw)
|
|
except ValueError:
|
|
raise errors.DateError()
|
|
|
|
|
|
def parse_time(value: Union[time, StrBytesIntFloat]) -> time:
|
|
"""
|
|
Parse a time/string and return a datetime.time.
|
|
|
|
Raise ValueError if the input is well formatted but not a valid time.
|
|
Raise ValueError if the input isn't well formatted, in particular if it contains an offset.
|
|
"""
|
|
if isinstance(value, time):
|
|
return value
|
|
|
|
number = get_numeric(value, 'time')
|
|
if number is not None:
|
|
if number >= 86400:
|
|
# doesn't make sense since the time time loop back around to 0
|
|
raise errors.TimeError()
|
|
return (datetime.min + timedelta(seconds=number)).time()
|
|
|
|
if isinstance(value, bytes):
|
|
value = value.decode()
|
|
|
|
match = time_re.match(value) # type: ignore
|
|
if match is None:
|
|
raise errors.TimeError()
|
|
|
|
kw = match.groupdict()
|
|
if kw['microsecond']:
|
|
kw['microsecond'] = kw['microsecond'].ljust(6, '0')
|
|
|
|
tzinfo = _parse_timezone(kw.pop('tzinfo'), errors.TimeError)
|
|
kw_: Dict[str, Union[None, int, timezone]] = {k: int(v) for k, v in kw.items() if v is not None}
|
|
kw_['tzinfo'] = tzinfo
|
|
|
|
try:
|
|
return time(**kw_) # type: ignore
|
|
except ValueError:
|
|
raise errors.TimeError()
|
|
|
|
|
|
def parse_datetime(value: Union[datetime, StrBytesIntFloat]) -> datetime:
|
|
"""
|
|
Parse a datetime/int/float/string and return a datetime.datetime.
|
|
|
|
This function supports time zone offsets. When the input contains one,
|
|
the output uses a timezone with a fixed offset from UTC.
|
|
|
|
Raise ValueError if the input is well formatted but not a valid datetime.
|
|
Raise ValueError if the input isn't well formatted.
|
|
"""
|
|
if isinstance(value, datetime):
|
|
return value
|
|
|
|
number = get_numeric(value, 'datetime')
|
|
if number is not None:
|
|
return from_unix_seconds(number)
|
|
|
|
if isinstance(value, bytes):
|
|
value = value.decode()
|
|
|
|
match = datetime_re.match(value) # type: ignore
|
|
if match is None:
|
|
raise errors.DateTimeError()
|
|
|
|
kw = match.groupdict()
|
|
if kw['microsecond']:
|
|
kw['microsecond'] = kw['microsecond'].ljust(6, '0')
|
|
|
|
tzinfo = _parse_timezone(kw.pop('tzinfo'), errors.DateTimeError)
|
|
kw_: Dict[str, Union[None, int, timezone]] = {k: int(v) for k, v in kw.items() if v is not None}
|
|
kw_['tzinfo'] = tzinfo
|
|
|
|
try:
|
|
return datetime(**kw_) # type: ignore
|
|
except ValueError:
|
|
raise errors.DateTimeError()
|
|
|
|
|
|
def parse_duration(value: StrBytesIntFloat) -> timedelta:
|
|
"""
|
|
Parse a duration int/float/string and return a datetime.timedelta.
|
|
|
|
The preferred format for durations in Django is '%d %H:%M:%S.%f'.
|
|
|
|
Also supports ISO 8601 representation.
|
|
"""
|
|
if isinstance(value, timedelta):
|
|
return value
|
|
|
|
if isinstance(value, (int, float)):
|
|
# below code requires a string
|
|
value = f'{value:f}'
|
|
elif isinstance(value, bytes):
|
|
value = value.decode()
|
|
|
|
try:
|
|
match = standard_duration_re.match(value) or iso8601_duration_re.match(value)
|
|
except TypeError:
|
|
raise TypeError('invalid type; expected timedelta, string, bytes, int or float')
|
|
|
|
if not match:
|
|
raise errors.DurationError()
|
|
|
|
kw = match.groupdict()
|
|
sign = -1 if kw.pop('sign', '+') == '-' else 1
|
|
if kw.get('microseconds'):
|
|
kw['microseconds'] = kw['microseconds'].ljust(6, '0')
|
|
|
|
if kw.get('seconds') and kw.get('microseconds') and kw['seconds'].startswith('-'):
|
|
kw['microseconds'] = '-' + kw['microseconds']
|
|
|
|
kw_ = {k: float(v) for k, v in kw.items() if v is not None}
|
|
|
|
return sign * timedelta(**kw_)
|