# -*- coding: utf-8 -*-
#
# Copyright (C) 2014-2019 Bitergia
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# Authors:
# Santiago Dueñas <sduenas@bitergia.com>
#
import re
from .models import MIN_PERIOD_DATE, MAX_PERIOD_DATE
[docs]def merge_datetime_ranges(dates, exclude_limits=False):
"""Merge datetime ranges.
Generator that merges overlapped datetime ranges. For example,
assuming all dates where set to the same time and are in UTC
timezone, these are some expected results:
* [(1900-01-01, 2010-01-01), (2008-01-01, 2100-01-01)]
--> [(1900-01-01, 2100-01-01)]
* [(1900-01-01, 2010-01-01), (2008-01-01, 2010-01-01), (2010-01-02, 2100-01-01)]
--> [(1900-01-01, 2010-01-01), (2011-01-02, 2100-01-01)]
* [(1900-01-01, 2010-01-01), (2010-01-02, 2100-01-01)]
--> [(1900-01-01, 2010-01-01), (2010-01-02, 2100-01-01)]
Default init and end dates (1900-01-01 and 2100-01-01) are
considered range limits. These will be removed when a set of
ranges overlaps and `exclude_limits` is set. Compare the next
examples with the ones from above:
* [(1900-01-01, 2010-01-01), (2008-01-01, 2100-01-01)]
--> [(2008-01-01, 2010-01-01)]
* [(1900-01-01, 2010-01-01), (2008-01-01, 2010-01-01), (2010-01-02, 2100-01-01)]
--> [(2008-01-01, 2010-01-01), (2010-01-02, 2100-01-01)]
* [(1900-01-01, 2010-01-01), (2010-01-02, 2100-01-01)]
--> [(1900-01-01, 2010-01-01), (2010-01-02, 2100-01-01)]
The condition MIN_PERIOD_DATE <= dt <= MAX_PERIOD_DATE must be
true for each date. Otherwise, the generator will raise a
`ValueError` exception.
:param dates: sequence of datetime ranges where each range is a
(start_date, end_date) tuple
:param exclude_limits: remove MIN_PERIOD_DATE and MAX_PERIOD_DATE
from overlapped ranges
:returns: a generator of merged datetime ranges where each range
is a (start_date, end_date) tuple
:raises ValueError: when a value of the data range is out of bounds
:raises TypeError: when timezone info is not set in any datetime object
"""
# This code is based on samplebias' answer to StackOverflow question
# "Merging a list of time-range tuples that have overlapping time-ranges"
# (http: // stackoverflow.com / questions / 5679638).
if not dates:
return
sorted_dates = sorted([sorted(t) for t in dates])
date_range = list(sorted_dates[0])
for start, end in sorted_dates:
if start < MIN_PERIOD_DATE or start > MAX_PERIOD_DATE:
raise ValueError("'start' date {} is out of bounds".format(start))
if end < MIN_PERIOD_DATE or end > MAX_PERIOD_DATE:
raise ValueError("'end' date {} is out of bounds".format(end))
if start <= date_range[1]:
if exclude_limits:
if date_range[0] == MIN_PERIOD_DATE:
date_range[0] = start
if MAX_PERIOD_DATE in (end, date_range[1]):
date_range[1] = min(date_range[1], end)
else:
date_range[1] = max(date_range[1], end)
else:
date_range[1] = max(date_range[1], end)
else:
yield tuple(date_range)
date_range[0] = start
date_range[1] = end
yield tuple(date_range)
[docs]def validate_field(name, value, allow_none=False):
"""Validate a given string field following a set of rules.
The conditions to validate `value` consists on checking if its value is `None`
and if this is allowed or not; if its value is not an empty string or if it is
not composed only by whitespaces and/or tabs.
:param name: name of the field to validate
:param value: value of the field to validate
:param allow_none: `True` if `None` values are permitted, `False` otherwise
:raises ValueError: when a condition to validate the string is not satisfied
:raises TypeError: when the input value is not a string and not `None`
"""
if value is None:
if not allow_none:
raise ValueError("'{}' cannot be None".format(name))
else:
return
if not isinstance(value, str):
msg = "field value must be a string; {} given".format(value.__class__.__name__)
raise TypeError(msg)
if value == '':
raise ValueError("'{}' cannot be an empty string".format(name))
m = re.match(r"^\s+$", value)
if m:
raise ValueError("'{}' cannot be composed by whitespaces only".format(name))