Change relative date's format to further simplify it

A relative date doesn't need to be prefixed by @ anymore.
The relative date pattern now displays named groups.
Digits have been change to [0-9] to avoid other digit characters.
Removed the @ character in tests.
Updated subsequent documentation.

Author: euri10

beets/dbcore/query.py

@@ -554,22 +554,25 @@ def parse(cls, string):
         relative.
         An absolute date has to be like one of the date_formats '%Y' or '%Y-%m'
         or '%Y-%m-%d'
-        A relative date begins by '@ 'and has to follow the pattern_dq format
-        '@([+|-]?)(\d+)([y|m|w|d])'
-        - '@' indicates it's a date relative to now()
-        - the optional '+' or '-' sign, which defaults to '+' will increment or
-        decrement now() by a certain quantity
-        - that quantity can be expressed in days, weeks, months or years
-        respectively 'd', 'w', 'm', 'y'
-        Please note that this relative calculation is rather approximate as it
-        makes the assumption of 30 days per month and 365 days per year
+        A relative date consists of three parts:
+        - a ``+`` or ``-`` sign is optional and defaults to ``+``. The ``+``
+        sign will add a time quantity to the current date while the ``-`` sign
+        will do the opposite
+        - a number follows and indicates the amount to add or substract
+        - a final letter ends and represents the amount in either days, weeks,
+        months or years (``d``, ``w``, ``m`` or ``y``)
+        Please note that this relative calculation makes the assumption of 30
+        days per month and 365 days per year.
         """
-        pattern_dq = '@([+|-]?)(\d+)([y|m|w|d])'
+
+        pattern_dq = '(?P<sign>[+|-]?)(?P<quantity>[0-9]+)(?P<timespan>[y|m|w|d])'  # noqa: E501
         match_dq = re.match(pattern_dq, string)
+        # test if the string matches the relative date pattern, add the parsed
+        # quantity to now in that case
         if match_dq is not None:
-            sign = match_dq.group(1)
-            quantity = match_dq.group(2)
-            timespan = match_dq.group(3)
+            sign = match_dq.group('sign')
+            quantity = match_dq.group('quantity')
+            timespan = match_dq.group('timespan')
             multiplier = -1 if sign == '-' else 1
             days = cls.relative[timespan]
             date = datetime.now() + multiplier * timedelta(

docs/reference/query.rst

@@ -166,8 +166,7 @@ You can also use relative dates to the current time.
 A relative date begins with an ``@``.
 It looks like ``@-3w``, ``@2m`` or ``@-4d`` which means the date 3 weeks ago,
 the date 2 months from now and the date 4 days ago.
-A relative date consists of four parts:
-- ``@`` indicates it's a date relative from now
+A relative date consists of three parts:
 - ``+`` or ``-`` sign is optional and defaults to ``+``. The ``+`` sign will
 add a time quantity to the current date while the ``-`` sign will do the
 opposite
@@ -180,11 +179,11 @@ month and 365 days per year.
 
 Here is an example that finds all the albums added between now and last week::
 
-    $ beet ls -a 'added:@-1w..'
+    $ beet ls -a 'added:-1w..'
 
-Find all items added in a 2 weeks period 4  weeks ago::
+Find all items added in a 2 weeks period 4 weeks ago::
 
-    $ beet ls -a 'added:@-6w..@-4w'
+    $ beet ls -a 'added:-6w..-4w'
 
 Date *intervals*, like the numeric intervals described above, are separated by
 two dots (``..``). You can specify a start, an end, or both.

test/test_datequery.py

@@ -47,8 +47,8 @@ def test_year_precision_intervals(self):
         self.assertContains('..2001', '2001-12-31T23:59:59')
         self.assertExcludes('..2001', '2002-01-01T00:00:00')
 
-        self.assertContains('@-1d..@1d', _datepattern(datetime.now()))
-        self.assertExcludes('@-2d..@-1d', _datepattern(datetime.now()))
+        self.assertContains('-1d..1d', _datepattern(datetime.now()))
+        self.assertExcludes('-2d..-1d', _datepattern(datetime.now()))
 
     def test_day_precision_intervals(self):
         self.assertContains('2000-06-20..2000-06-20', '2000-06-20T00:00:00')
@@ -168,37 +168,37 @@ def setUp(self):
 
     def test_relative(self):
         for timespan in ['d', 'w', 'm', 'y']:
-            query = DateQuery('added', '@-4' + timespan + '..@+4' + timespan)
+            query = DateQuery('added', '-4' + timespan + '..+4' + timespan)
             matched = self.lib.items(query)
             self.assertEqual(len(matched), 1)
 
     def test_relative_fail(self):
         for timespan in ['d', 'w', 'm', 'y']:
-            query = DateQuery('added', '@-2' + timespan + '..@-1' + timespan)
+            query = DateQuery('added', '-2' + timespan + '..-1' + timespan)
             matched = self.lib.items(query)
             self.assertEqual(len(matched), 0)
 
     def test_start_relative(self):
         for timespan in ['d', 'w', 'm', 'y']:
-            query = DateQuery('added', '@-4' + timespan + '..')
+            query = DateQuery('added', '-4' + timespan + '..')
             matched = self.lib.items(query)
             self.assertEqual(len(matched), 1)
 
     def test_start_relative_fail(self):
         for timespan in ['d', 'w', 'm', 'y']:
-            query = DateQuery('added', '@4' + timespan + '..')
+            query = DateQuery('added', '4' + timespan + '..')
             matched = self.lib.items(query)
             self.assertEqual(len(matched), 0)
 
     def test_end_relative(self):
         for timespan in ['d', 'w', 'm', 'y']:
-            query = DateQuery('added', '..@+4' + timespan)
+            query = DateQuery('added', '..+4' + timespan)
             matched = self.lib.items(query)
             self.assertEqual(len(matched), 1)
 
     def test_end_relative_fail(self):
         for timespan in ['d', 'w', 'm', 'y']:
-            query = DateQuery('added', '..@-4' + timespan)
+            query = DateQuery('added', '..-4' + timespan)
             matched = self.lib.items(query)
             self.assertEqual(len(matched), 0)