diff options
Diffstat (limited to 'src/isodate/isodates.py')
| -rw-r--r-- | src/isodate/isodates.py | 171 |
1 files changed, 80 insertions, 91 deletions
diff --git a/src/isodate/isodates.py b/src/isodate/isodates.py index aab5684..3c5c095 100644 --- a/src/isodate/isodates.py +++ b/src/isodate/isodates.py @@ -1,37 +1,11 @@ -############################################################################## -# Copyright 2009, Gerhard Weis -# All rights reserved. -# -# Redistribution and use in source and binary forms, with or without -# modification, are permitted provided that the following conditions are met: -# -# * Redistributions of source code must retain the above copyright notice, -# this list of conditions and the following disclaimer. -# * Redistributions in binary form must reproduce the above copyright notice, -# this list of conditions and the following disclaimer in the documentation -# and/or other materials provided with the distribution. -# * Neither the name of the authors nor the names of its contributors -# may be used to endorse or promote products derived from this software -# without specific prior written permission. -# -# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" -# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE -# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE -# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE -# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR -# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF -# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS -# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN -# CONTRACT, STRICT LIABILITY, OR TORT -############################################################################## -''' +""" This modules provides a method to parse an ISO 8601:2004 date string to a python datetime.date instance. It supports all basic, extended and expanded formats as described in the ISO standard. The only limitations it has, are given by the Python datetime.date implementation, which does not support dates before 0001-01-01. -''' +""" import re from datetime import date, timedelta @@ -46,7 +20,7 @@ DATE_REGEX_CACHE = {} def build_date_regexps(yeardigits=4, expanded=False): - ''' + """ Compile set of regular expressions to parse ISO dates. The expressions will be created only if they are not already in REGEX_CACHE. @@ -56,7 +30,7 @@ def build_date_regexps(yeardigits=4, expanded=False): ISO 8601 allows more than 4 digit years, on prior agreement, but then a +/- sign is required (expanded format). To support +/- sign for 4 digit years, the expanded parameter needs to be set to True. - ''' + """ if yeardigits != 4: expanded = True if (yeardigits, expanded) not in DATE_REGEX_CACHE: @@ -67,69 +41,82 @@ def build_date_regexps(yeardigits=4, expanded=False): sign = 1 else: sign = 0 + + def add_re(regex_text): + cache_entry.append(re.compile(r"\A" + regex_text + r"\Z")) + # 1. complete dates: # YYYY-MM-DD or +- YYYYYY-MM-DD... extended date format - cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" - r"-(?P<month>[0-9]{2})-(?P<day>[0-9]{2})" - % (sign, yeardigits))) + add_re( + r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" + r"-(?P<month>[0-9]{2})-(?P<day>[0-9]{2})" % (sign, yeardigits) + ) # YYYYMMDD or +- YYYYYYMMDD... basic date format - cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" - r"(?P<month>[0-9]{2})(?P<day>[0-9]{2})" - % (sign, yeardigits))) + add_re( + r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" + r"(?P<month>[0-9]{2})(?P<day>[0-9]{2})" % (sign, yeardigits) + ) # 2. complete week dates: # YYYY-Www-D or +-YYYYYY-Www-D ... extended week date - cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" - r"-W(?P<week>[0-9]{2})-(?P<day>[0-9]{1})" - % (sign, yeardigits))) + add_re( + r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" + r"-W(?P<week>[0-9]{2})-(?P<day>[0-9]{1})" % (sign, yeardigits) + ) # YYYYWwwD or +-YYYYYYWwwD ... basic week date - cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})W" - r"(?P<week>[0-9]{2})(?P<day>[0-9]{1})" - % (sign, yeardigits))) + add_re( + r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})W" + r"(?P<week>[0-9]{2})(?P<day>[0-9]{1})" % (sign, yeardigits) + ) # 3. ordinal dates: # YYYY-DDD or +-YYYYYY-DDD ... extended format - cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" - r"-(?P<day>[0-9]{3})" - % (sign, yeardigits))) + add_re( + r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" + r"-(?P<day>[0-9]{3})" % (sign, yeardigits) + ) # YYYYDDD or +-YYYYYYDDD ... basic format - cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" - r"(?P<day>[0-9]{3})" - % (sign, yeardigits))) + add_re( + r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" + r"(?P<day>[0-9]{3})" % (sign, yeardigits) + ) + # 4. week dates: + # YYYY-Www or +-YYYYYY-Www ... extended reduced accuracy week date # 4. week dates: # YYYY-Www or +-YYYYYY-Www ... extended reduced accuracy week date - cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" - r"-W(?P<week>[0-9]{2})" - % (sign, yeardigits))) + add_re( + r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" + r"-W(?P<week>[0-9]{2})" % (sign, yeardigits) + ) # YYYYWww or +-YYYYYYWww ... basic reduced accuracy week date - cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})W" - r"(?P<week>[0-9]{2})" - % (sign, yeardigits))) + add_re( + r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})W" + r"(?P<week>[0-9]{2})" % (sign, yeardigits) + ) + # 5. month dates: + # YYY-MM or +-YYYYYY-MM ... reduced accuracy specific month # 5. month dates: # YYY-MM or +-YYYYYY-MM ... reduced accuracy specific month - cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" - r"-(?P<month>[0-9]{2})" - % (sign, yeardigits))) + add_re( + r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" + r"-(?P<month>[0-9]{2})" % (sign, yeardigits) + ) # YYYMM or +-YYYYYYMM ... basic incomplete month date format - cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" - r"(?P<month>[0-9]{2})" - % (sign, yeardigits))) + add_re( + r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" + r"(?P<month>[0-9]{2})" % (sign, yeardigits) + ) # 6. year dates: # YYYY or +-YYYYYY ... reduced accuracy specific year - cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" - % (sign, yeardigits))) + add_re(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" % (sign, yeardigits)) # 7. century dates: # YY or +-YYYY ... reduced accuracy specific century - cache_entry.append(re.compile(r"(?P<sign>[+-]){%d}" - r"(?P<century>[0-9]{%d})" - % (sign, yeardigits - 2))) + add_re(r"(?P<sign>[+-]){%d}" r"(?P<century>[0-9]{%d})" % (sign, yeardigits - 2)) DATE_REGEX_CACHE[(yeardigits, expanded)] = cache_entry return DATE_REGEX_CACHE[(yeardigits, expanded)] -def parse_date( - datestring, - yeardigits=4, expanded=False, defaultmonth=1, defaultday=1): - ''' +def parse_date(datestring, yeardigits=4, expanded=False, defaultmonth=1, defaultday=1): + """ Parse an ISO 8601 date string into a datetime.date object. As the datetime.date implementation is limited to dates starting from @@ -162,7 +149,7 @@ def parse_date( @return: a datetime.date instance represented by datestring @raise ISO8601Error: if this function can not parse the datestring @raise ValueError: if datestring can not be represented by datetime.date - ''' + """ if yeardigits != 4: expanded = True isodates = build_date_regexps(yeardigits, expanded) @@ -172,42 +159,44 @@ def parse_date( groups = match.groupdict() # sign, century, year, month, week, day, # FIXME: negative dates not possible with python standard types - sign = (groups['sign'] == '-' and -1) or 1 - if 'century' in groups: + sign = (groups["sign"] == "-" and -1) or 1 + if "century" in groups: return date( - sign * (int(groups['century']) * 100 + 1), - defaultmonth, defaultday) - if 'month' not in groups: # weekdate or ordinal date - ret = date(sign * int(groups['year']), 1, 1) - if 'week' in groups: + sign * (int(groups["century"]) * 100 + 1), defaultmonth, defaultday + ) + if "month" not in groups: # weekdate or ordinal date + ret = date(sign * int(groups["year"]), 1, 1) + if "week" in groups: isotuple = ret.isocalendar() - if 'day' in groups: - days = int(groups['day'] or 1) + if "day" in groups: + days = int(groups["day"] or 1) else: days = 1 # if first week in year, do weeks-1 - return ret + timedelta(weeks=int(groups['week']) - - (((isotuple[1] == 1) and 1) or 0), - days=-isotuple[2] + days) - elif 'day' in groups: # ordinal date - return ret + timedelta(days=int(groups['day']) - 1) + return ret + timedelta( + weeks=int(groups["week"]) - (((isotuple[1] == 1) and 1) or 0), + days=-isotuple[2] + days, + ) + elif "day" in groups: # ordinal date + return ret + timedelta(days=int(groups["day"]) - 1) else: # year date return ret.replace(month=defaultmonth, day=defaultday) # year-, month-, or complete date - if 'day' not in groups or groups['day'] is None: + if "day" not in groups or groups["day"] is None: day = defaultday else: - day = int(groups['day']) - return date(sign * int(groups['year']), - int(groups['month']) or defaultmonth, day) - raise ISO8601Error('Unrecognised ISO 8601 date format: %r' % datestring) + day = int(groups["day"]) + return date( + sign * int(groups["year"]), int(groups["month"]) or defaultmonth, day + ) + raise ISO8601Error("Unrecognised ISO 8601 date format: %r" % datestring) def date_isoformat(tdate, format=DATE_EXT_COMPLETE, yeardigits=4): - ''' + """ Format date strings. This method is just a wrapper around isodate.isostrf.strftime and uses Date-Extended-Complete as default format. - ''' + """ return strftime(tdate, format, yeardigits) |