refactor(regex): use regex

pydantic/datetime_parse.py

@@ -54,6 +54,9 @@
     r'$'
 )
 
+# Support scientific notation
+scientific_notation = re.compile(r'^(?P<sign>[-+]?)' r'(?P<scientific_notation>\d+(.\d+)?[eE][+\-]?\d+)?' r'$')
+
 EPOCH = datetime(1970, 1, 1)
 # if greater than this, the number is in ms, if less than or equal it's in seconds
 # (in seconds this is 11th October 2603, in ms it's 20th August 1970)
@@ -226,16 +229,11 @@ def parse_duration(value: StrBytesIntFloat) -> timedelta:
         value = str(value)
     elif isinstance(value, bytes):
         value = value.decode()
-
-    if isinstance(value, (str)):
-        try:
-            #scientific notation
-            value = f"{float(value):.6f}"
-        except ValueError:
-            pass
-
+
     try:
-        match = standard_duration_re.match(value) or iso8601_duration_re.match(value)
+        match = (
+            standard_duration_re.match(value) or iso8601_duration_re.match(value) or scientific_notation.match(value)
+        )
     except TypeError:
         raise TypeError('invalid type; expected timedelta, string, bytes, int or float')
 
@@ -250,6 +248,9 @@ def parse_duration(value: StrBytesIntFloat) -> timedelta:
     if kw.get('seconds') and kw.get('microseconds') and kw['seconds'].startswith('-'):
         kw['microseconds'] = '-' + kw['microseconds']
 
+    if kw.get('scientific_notation'):
+        kw['seconds'] = ("%.17s" % kw.pop('scientific_notation')).rstrip('0').rstrip('.')
+
     kw_ = {k: float(v) for k, v in kw.items() if v is not None}
 
     return sign * timedelta(**kw_)  # type: ignore

tests/test_datetime_parse.py

@@ -160,7 +160,7 @@ def test_datetime_parsing(value, result):
         timedelta(days=-4, minutes=15, seconds=30),  # negative durations
         timedelta(minutes=15, seconds=30),  # minute & seconds
         timedelta(seconds=30),  # seconds
-        timedelta(microseconds=99)  # microseconds
+        timedelta(microseconds=99),  # microseconds
     ],
 )
 def test_parse_python_format(delta):
@@ -212,14 +212,14 @@ def test_parse_python_format(delta):
         ('PT0.000005S', timedelta(microseconds=5)),
         (b'PT0.000005S', timedelta(microseconds=5)),
         # Scientific Notation
-        ('+0003', timedelta(seconds=3)),
+        ('+0003', errors.DurationError),
         (9.9e-05, timedelta(microseconds=99)),
         ('9.9e-05', timedelta(microseconds=99)),
         (9.9e05, timedelta(days=11, seconds=39600)),
         (+3, timedelta(seconds=3)),
-        (-4.70e+9, timedelta(days=-54399, seconds=73600)),
-        (-.2E-4, timedelta(days=-1, seconds=86399, microseconds=999980)),
-        (-7.6603, timedelta(days=-1, seconds=86392, microseconds=339700))
+        (-4.70e9, timedelta(days=-54399, seconds=73600)),
+        (-0.2e-4, timedelta(days=-1, seconds=86399, microseconds=999980)),
+        (-7.6603, timedelta(days=-1, seconds=86392, microseconds=339700)),
     ],
 )
 def test_parse_durations(value, result):