ISO 8601 parser for the examples

Author: jml

examples/iso8601.py

@@ -0,0 +1,41 @@
+import datetime
+import pytz
+
+from parsley import makeGrammar
+
+# See www.ietf.org/rfc/rfc3339.txt
+
+_iso_8601_definition = r"""
+year = <digit{4}>:Y -> int(Y)
+month = <digit{2}>:m -> int(m)
+day = <digit{2}>:d -> int(d)
+
+hour = <digit{2}>:H -> int(H)
+minute = <digit{2}>:M -> int(M)
+second = <digit{2}>:S -> int(S)
+fraction = '.' <digit+>:frac -> int(float('0.' + frac) * 10 ** 6)
+
+sign = ('-' -> -1) | ('+' -> 1)
+numeric_offset = sign:s hour:h ':' minute:m -> FixedOffset(s * (h * 60 + m))
+utc = 'Z' -> UTC
+offset = utc | numeric_offset
+
+naive_time = hour:h ':' minute:m ':' second:s (fraction | -> 0):ms
+             -> time(h, m, s, ms)
+time = naive_time:t offset:o -> t.replace(tzinfo=o)
+date = year:y '-' month:m '-' day:d -> date(y, m, d)
+
+datetime = date:d 'T' time:t -> datetime.combine(d, t)
+"""
+
+
+DateTimeParser = makeGrammar(
+    _iso_8601_definition,
+    {
+        'FixedOffset': pytz.FixedOffset,
+        'date': datetime.date,
+        'time': datetime.time,
+        'datetime': datetime.datetime,
+        'UTC': pytz.UTC,
+    },
+)

examples/test_iso8601.py

@@ -0,0 +1,56 @@
+import datetime
+import unittest
+
+import pytz
+
+from iso8601 import DateTimeParser
+
+
+class TestDatetimeParsing(unittest.TestCase):
+
+    def test_date(self):
+        self.assertEqual(
+            datetime.date(2001, 12, 25),
+            DateTimeParser('2001-12-25').date())
+
+    def test_naive_time(self):
+        self.assertEqual(
+            datetime.time(13, 59, 43),
+            DateTimeParser('13:59:43').naive_time())
+
+    def test_fractional_naive_time(self):
+        self.assertEqual(
+            datetime.time(13, 59, 43, 880000),
+            DateTimeParser('13:59:43.88').naive_time())
+
+    def test_utc_time(self):
+        self.assertEqual(
+            datetime.time(13, 59, 43, tzinfo=pytz.UTC),
+            DateTimeParser('13:59:43Z').time())
+
+    def test_fractional_utc_time(self):
+        self.assertEqual(
+            datetime.time(13, 59, 43, 880000, tzinfo=pytz.UTC),
+            DateTimeParser('13:59:43.88Z').time())
+
+    def test_timezone_time(self):
+        self.assertEqual(
+            datetime.time(13, 59, 43, tzinfo=pytz.FixedOffset(60)),
+            DateTimeParser('13:59:43+01:00').time())
+
+    def test_fractional_timezone_time(self):
+        self.assertEqual(
+            datetime.time(13, 59, 43, 770000, tzinfo=pytz.FixedOffset(60)),
+            DateTimeParser('13:59:43.77+01:00').time())
+
+    def test_numeric_offset(self):
+        get_offset = lambda x: DateTimeParser(x).numeric_offset()
+        self.assertEqual(pytz.FixedOffset(0), get_offset('+00:00'))
+        self.assertEqual(pytz.FixedOffset(90), get_offset('+01:30'))
+        self.assertEqual(pytz.FixedOffset(-150), get_offset('-02:30'))
+
+    def test_datetime(self):
+        self.assertEqual(
+            datetime.datetime(
+                2001, 12, 25, 13, 59, 43, 770000, tzinfo=pytz.UTC),
+            DateTimeParser('2001-12-25T13:59:43.77Z').datetime())