Python parser: date string -> date object.

date_parser.py

import datetime

from re import match

date_separator = r'(/|-|.)'
time_separator = r'(:|-|.)'
date_formats = '"D/M/YYYY" | "D-M-YYYY" | "D.M.YYYY"'
datetime_formats = '"D/M/YYYY H:M:S" | "D-M-YYYY H-M-S" | "D.M.YYYY H.M.S"'


def datetime_input(regex_verbose=date_formats, input_time=True, timezone=False, initial=True, date=None, required=True,
                   message='Specify a date', regex=r'(?P<day>[0-9]+)' + date_separator +
                                                   r'(?P<month>[0-9]+)' + date_separator +
                                                   r'(?P<year>[0-9]{4})'):
    """
    :param date: String date to return date object (optional)
    :param required: Ends only with a valid date (ignored if "date" is sent) (defaults to True)
    :param message: Message to be shown as message for input (ignored if "date" is sent)
    :param regex: Regex to match the string date
    :param regex_verbose: Date format to be shown to the user
    :param initial: Specifies the beginning or the end of the specified date (ignored if time is sent with the date)
    :param timezone: Specifies if timezone will be included in the "datetime" object
    :param input_time: Defines if the time will be sent
    :return: "DateTime" object ("False" if no input is provided and not required)
    """
    if input_time:
        regex += (r'\s((?P<hour>[0-9]+)' + time_separator +
                  r'(?P<minute>[0-9]+)' + time_separator +
                  r'(?P<second>[0-9]+))?')
        regex_verbose = datetime_formats

    if date:
        date = match(regex, date)
        if not date:
            raise ValidationError('Sent an invalid date format. Format: ' + regex_verbose)

    else:
        executed_once = date = False

        input_message = '{message} {required}({regex_verbose}): '.format(
            message=message,
            required='' if required else '(leave empty to continue)',
            regex_verbose=regex_verbose
        )

        while not date:
            if executed_once:
                print('Provide a valid value.')

            date = raw_input(input_message)

            # User must leave empty if doesn't want to specify it
            if not date and not required:
                return False

            date = match(regex, date)
            executed_once = True

    date = date.groupdict()
    # The values are string (parse them to integer)
    for key, value in date.items():
        if value is None:
            del date[key]
        else:
            date[key] = int(value)

    if timezone:
        from django.utils import timezone
        date_object = timezone.now().replace(**date)
    else:
        date_object = datetime.datetime(**date)

    if not ('hour' in date and 'minute' in date and 'second' in date):
        # Set the time
        time = date_object.time().min if initial else date_object.time().max
        date_object = datetime.datetime.combine(date_object, time)

    return date_object