Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/isodate/isodates.py: 15%

1""" 

2This modules provides a method to parse an ISO 8601:2004 date string to a 

3python datetime.date instance. 

4 

5It supports all basic, extended and expanded formats as described in the ISO 

6standard. The only limitations it has, are given by the Python datetime.date 

7implementation, which does not support dates before 0001-01-01. 

8""" 

9 

10import re 

11from datetime import date, timedelta 

12 

13from isodate.isoerror import ISO8601Error 

14from isodate.isostrf import DATE_EXT_COMPLETE, strftime 

15 

16DATE_REGEX_CACHE = {} 

17# A dictionary to cache pre-compiled regular expressions. 

18# A set of regular expressions is identified, by number of year digits allowed 

19# and whether a plus/minus sign is required or not. (This option is changeable 

20# only for 4 digit years). 

21 

22 

23def build_date_regexps(yeardigits=4, expanded=False): 

24 """ 

25 Compile set of regular expressions to parse ISO dates. The expressions will 

26 be created only if they are not already in REGEX_CACHE. 

27 

28 It is necessary to fix the number of year digits, else it is not possible 

29 to automatically distinguish between various ISO date formats. 

30 

31 ISO 8601 allows more than 4 digit years, on prior agreement, but then a +/- 

32 sign is required (expanded format). To support +/- sign for 4 digit years, 

33 the expanded parameter needs to be set to True. 

34 """ 

35 if yeardigits != 4: 

36 expanded = True 

37 if (yeardigits, expanded) not in DATE_REGEX_CACHE: 

38 cache_entry = [] 

39 # ISO 8601 expanded DATE formats allow an arbitrary number of year 

40 # digits with a leading +/- sign. 

41 if expanded: 

42 sign = 1 

43 else: 

44 sign = 0 

45 

46 def add_re(regex_text): 

47 cache_entry.append(re.compile(r"\A" + regex_text + r"\Z")) 

48 

49 # 1. complete dates: 

50 # YYYY-MM-DD or +- YYYYYY-MM-DD... extended date format 

51 add_re( 

52 r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" 

53 r"-(?P<month>[0-9]{2})-(?P<day>[0-9]{2})" % (sign, yeardigits) 

54 ) 

55 # YYYYMMDD or +- YYYYYYMMDD... basic date format 

56 add_re( 

57 r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" 

58 r"(?P<month>[0-9]{2})(?P<day>[0-9]{2})" % (sign, yeardigits) 

59 ) 

60 # 2. complete week dates: 

61 # YYYY-Www-D or +-YYYYYY-Www-D ... extended week date 

62 add_re( 

63 r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" 

64 r"-W(?P<week>[0-9]{2})-(?P<day>[0-9]{1})" % (sign, yeardigits) 

65 ) 

66 # YYYYWwwD or +-YYYYYYWwwD ... basic week date 

67 add_re( 

68 r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})W" 

69 r"(?P<week>[0-9]{2})(?P<day>[0-9]{1})" % (sign, yeardigits) 

70 ) 

71 # 3. ordinal dates: 

72 # YYYY-DDD or +-YYYYYY-DDD ... extended format 

73 add_re( 

74 r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" 

75 r"-(?P<day>[0-9]{3})" % (sign, yeardigits) 

76 ) 

77 # YYYYDDD or +-YYYYYYDDD ... basic format 

78 add_re( 

79 r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" 

80 r"(?P<day>[0-9]{3})" % (sign, yeardigits) 

81 ) 

82 # 4. week dates: 

83 # YYYY-Www or +-YYYYYY-Www ... extended reduced accuracy week date 

84 # 4. week dates: 

85 # YYYY-Www or +-YYYYYY-Www ... extended reduced accuracy week date 

86 add_re( 

87 r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" 

88 r"-W(?P<week>[0-9]{2})" % (sign, yeardigits) 

89 ) 

90 # YYYYWww or +-YYYYYYWww ... basic reduced accuracy week date 

91 add_re( 

92 r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})W" 

93 r"(?P<week>[0-9]{2})" % (sign, yeardigits) 

94 ) 

95 # 5. month dates: 

96 # YYY-MM or +-YYYYYY-MM ... reduced accuracy specific month 

97 # 5. month dates: 

98 # YYY-MM or +-YYYYYY-MM ... reduced accuracy specific month 

99 add_re( 

100 r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" 

101 r"-(?P<month>[0-9]{2})" % (sign, yeardigits) 

102 ) 

103 # YYYMM or +-YYYYYYMM ... basic incomplete month date format 

104 add_re( 

105 r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" 

106 r"(?P<month>[0-9]{2})" % (sign, yeardigits) 

107 ) 

108 # 6. year dates: 

109 # YYYY or +-YYYYYY ... reduced accuracy specific year 

110 add_re(r"(?P<sign>[+-]){%d}(?P<year>[0-9]{%d})" % (sign, yeardigits)) 

111 # 7. century dates: 

112 # YY or +-YYYY ... reduced accuracy specific century 

113 add_re(r"(?P<sign>[+-]){%d}" r"(?P<century>[0-9]{%d})" % (sign, yeardigits - 2)) 

114 

115 DATE_REGEX_CACHE[(yeardigits, expanded)] = cache_entry 

116 return DATE_REGEX_CACHE[(yeardigits, expanded)] 

117 

118 

119def parse_date(datestring, yeardigits=4, expanded=False, defaultmonth=1, defaultday=1): 

120 """ 

121 Parse an ISO 8601 date string into a datetime.date object. 

122 

123 As the datetime.date implementation is limited to dates starting from 

124 0001-01-01, negative dates (BC) and year 0 can not be parsed by this 

125 method. 

126 

127 For incomplete dates, this method chooses the first day for it. For 

128 instance if only a century is given, this method returns the 1st of 

129 January in year 1 of this century. 

130 

131 supported formats: (expanded formats are shown with 6 digits for year) 

132 YYYYMMDD +-YYYYYYMMDD basic complete date 

133 YYYY-MM-DD +-YYYYYY-MM-DD extended complete date 

134 YYYYWwwD +-YYYYYYWwwD basic complete week date 

135 YYYY-Www-D +-YYYYYY-Www-D extended complete week date 

136 YYYYDDD +-YYYYYYDDD basic ordinal date 

137 YYYY-DDD +-YYYYYY-DDD extended ordinal date 

138 YYYYWww +-YYYYYYWww basic incomplete week date 

139 YYYY-Www +-YYYYYY-Www extended incomplete week date 

140 YYYMM +-YYYYYYMM basic incomplete month date 

141 YYY-MM +-YYYYYY-MM incomplete month date 

142 YYYY +-YYYYYY incomplete year date 

143 YY +-YYYY incomplete century date 

144 

145 @param datestring: the ISO date string to parse 

146 @param yeardigits: how many digits are used to represent a year 

147 @param expanded: if True then +/- signs are allowed. This parameter 

148 is forced to True, if yeardigits != 4 

149 

150 @return: a datetime.date instance represented by datestring 

151 @raise ISO8601Error: if this function can not parse the datestring 

152 @raise ValueError: if datestring can not be represented by datetime.date 

153 """ 

154 if yeardigits != 4: 

155 expanded = True 

156 isodates = build_date_regexps(yeardigits, expanded) 

157 for pattern in isodates: 

158 match = pattern.match(datestring) 

159 if match: 

160 groups = match.groupdict() 

161 # sign, century, year, month, week, day, 

162 # FIXME: negative dates not possible with python standard types 

163 sign = (groups["sign"] == "-" and -1) or 1 

164 if "century" in groups: 

165 return date( 

166 sign * (int(groups["century"]) * 100 + 1), defaultmonth, defaultday 

167 ) 

168 if "month" not in groups: # weekdate or ordinal date 

169 ret = date(sign * int(groups["year"]), 1, 1) 

170 if "week" in groups: 

171 isotuple = ret.isocalendar() 

172 if "day" in groups: 

173 days = int(groups["day"] or 1) 

174 else: 

175 days = 1 

176 # if first week in year, do weeks-1 

177 return ret + timedelta( 

178 weeks=int(groups["week"]) - (((isotuple[1] == 1) and 1) or 0), 

179 days=-isotuple[2] + days, 

180 ) 

181 elif "day" in groups: # ordinal date 

182 return ret + timedelta(days=int(groups["day"]) - 1) 

183 else: # year date 

184 return ret.replace(month=defaultmonth, day=defaultday) 

185 # year-, month-, or complete date 

186 if "day" not in groups or groups["day"] is None: 

187 day = defaultday 

188 else: 

189 day = int(groups["day"]) 

190 return date( 

191 sign * int(groups["year"]), int(groups["month"]) or defaultmonth, day 

192 ) 

193 raise ISO8601Error("Unrecognised ISO 8601 date format: %r" % datestring) 

194 

195 

196def date_isoformat(tdate, format=DATE_EXT_COMPLETE, yeardigits=4): 

197 """ 

198 Format date strings. 

199 

200 This method is just a wrapper around isodate.isostrf.strftime and uses 

201 Date-Extended-Complete as default format. 

202 """ 

203 return strftime(tdate, format, yeardigits)