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Source code for django.utils.dateparse

"""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.

import datetime
import re
from django.utils import six
from django.utils.timezone import utc, get_fixed_timezone


date_re = re.compile(
    r'(?P<year>\d{4})-(?P<month>\d{1,2})-(?P<day>\d{1,2})$'
)

time_re = re.compile(
    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})?)?'
)

datetime_re = re.compile(
    r'(?P<year>\d{4})-(?P<month>\d{1,2})-(?P<day>\d{1,2})'
    r'[T ](?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})?)?$'
)


[docs]def parse_date(value): """Parses a string and return a datetime.date. Raises ValueError if the input is well formatted but not a valid date. Returns None if the input isn't well formatted. """ match = date_re.match(value) if match: kw = dict((k, int(v)) for k, v in six.iteritems(match.groupdict())) return datetime.date(**kw)
[docs]def parse_time(value): """Parses a string and return a datetime.time. This function doesn't support time zone offsets. Raises ValueError if the input is well formatted but not a valid time. Returns None if the input isn't well formatted, in particular if it contains an offset. """ match = time_re.match(value) if match: kw = match.groupdict() if kw['microsecond']: kw['microsecond'] = kw['microsecond'].ljust(6, '0') kw = dict((k, int(v)) for k, v in six.iteritems(kw) if v is not None) return datetime.time(**kw)
[docs]def parse_datetime(value): """Parses a 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. Raises ValueError if the input is well formatted but not a valid datetime. Returns None if the input isn't well formatted. """ match = datetime_re.match(value) if match: kw = match.groupdict() if kw['microsecond']: kw['microsecond'] = kw['microsecond'].ljust(6, '0') tzinfo = kw.pop('tzinfo') if tzinfo == 'Z': tzinfo = utc elif tzinfo is not None: offset_mins = int(tzinfo[-2:]) if len(tzinfo) > 3 else 0 offset = 60 * int(tzinfo[1:3]) + offset_mins if tzinfo[0] == '-': offset = -offset tzinfo = get_fixed_timezone(offset) kw = dict((k, int(v)) for k, v in six.iteritems(kw) if v is not None) kw['tzinfo'] = tzinfo return datetime.datetime(**kw)
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