implement '--range' with Python ranges

gallery_dl/util.py

@@ -714,29 +714,33 @@ def chain_predicates(predicates, url, kwdict):
 
 
 class RangePredicate():
-    """Predicate; True if the current index is in the given range"""
+    """Predicate; True if the current index is in the given range(s)"""
+
     def __init__(self, rangespec):
-        self.ranges = self.optimize_range(self.parse_range(rangespec))
+        self.ranges = ranges = self._parse(rangespec)
         self.index = 0
 
-        if self.ranges:
-            self.lower, self.upper = self.ranges[0][0], self.ranges[-1][1]
+        if ranges:
+            # technically wrong, but good enough for now
+            # and evaluating min/max for a öarge range is slow
+            self.lower = min(r.start for r in ranges)
+            self.upper = max(r.stop for r in ranges) - 1
         else:
-            self.lower, self.upper = 0, 0
+            self.lower = self.upper = 0
 
-    def __call__(self, url, _):
-        self.index += 1
+    def __call__(self, _url, _kwdict):
+        self.index = index = self.index + 1
 
-        if self.index > self.upper:
+        if index > self.upper:
             raise exception.StopExtraction()
 
-        for lower, upper in self.ranges:
-            if lower <= self.index <= upper:
+        for range in self.ranges:
+            if index in range:
                 return True
         return False
 
     @staticmethod
-    def parse_range(rangespec):
+    def _parse(rangespec):
         """Parse an integer range string and return the resulting ranges
 
         Examples:
@@ -744,22 +748,29 @@ class RangePredicate():
             parse_range(" - 3 , 4-  4, 2-6") -> [(1,3), (4,4), (2,6)]
         """
         ranges = []
+        append = ranges.append
+
+        if isinstance(rangespec, str):
+            rangespec = rangespec.split(",")
 
-        for group in rangespec.split(","):
+        for group in rangespec:
             if not group:
                 continue
+
             first, sep, last = group.partition("-")
-            if not sep:
-                beg = end = int(first)
+            if sep:
+                append(range(
+                    int(first) if first.strip() else 1,
+                    int(last) + 1 if last.strip() else sys.maxsize,
+                ))
             else:
-                beg = int(first) if first.strip() else 1
-                end = int(last) if last.strip() else sys.maxsize
-            ranges.append((beg, end) if beg <= end else (end, beg))
+                v = int(first)
+                append(range(v, v+1))
 
         return ranges
 
     @staticmethod
-    def optimize_range(ranges):
+    def _optimize(ranges):
         """Simplify/Combine a parsed list of ranges
 
         Examples:

test/test_util.py

@@ -24,39 +24,32 @@ from gallery_dl import util, text, exception  # noqa E402
 
 class TestRange(unittest.TestCase):
 
-    def test_parse_range(self, f=util.RangePredicate.parse_range):
+    def test_parse_range(self, f=util.RangePredicate._parse):
         self.assertEqual(
             f(""),
-            [])
+            [],
+        )
         self.assertEqual(
             f("1-2"),
-            [(1, 2)])
+            [range(1, 3)],
+        )
         self.assertEqual(
             f("-"),
-            [(1, sys.maxsize)])
+            [range(1, sys.maxsize)],
+        )
         self.assertEqual(
             f("-2,4,6-8,10-"),
-            [(1, 2), (4, 4), (6, 8), (10, sys.maxsize)])
+            [range(1, 3),
+             range(4, 5),
+             range(6, 9),
+             range(10, sys.maxsize)],
+        )
         self.assertEqual(
             f(" - 3 , 4-  4, 2-6"),
-            [(1, 3), (4, 4), (2, 6)])
-
-    def test_optimize_range(self, f=util.RangePredicate.optimize_range):
-        self.assertEqual(
-            f([]),
-            [])
-        self.assertEqual(
-            f([(2, 4)]),
-            [(2, 4)])
-        self.assertEqual(
-            f([(2, 4), (6, 8), (10, 12)]),
-            [(2, 4), (6, 8), (10, 12)])
-        self.assertEqual(
-            f([(2, 4), (4, 6), (5, 8)]),
-            [(2, 8)])
-        self.assertEqual(
-            f([(1, 1), (2, 2), (3, 6), (8, 9)]),
-            [(1, 6), (8, 9)])
+            [range(1, 4),
+             range(4, 5),
+             range(2, 7)],
+        )
 
 
 class TestPredicate(unittest.TestCase):
@@ -68,7 +61,7 @@ class TestPredicate(unittest.TestCase):
         for i in range(6):
             self.assertTrue(pred(dummy, dummy))
         with self.assertRaises(exception.StopExtraction):
-            bool(pred(dummy, dummy))
+            pred(dummy, dummy)
 
         pred = util.RangePredicate("1, 3, 5")
         self.assertTrue(pred(dummy, dummy))
@@ -77,11 +70,11 @@ class TestPredicate(unittest.TestCase):
         self.assertFalse(pred(dummy, dummy))
         self.assertTrue(pred(dummy, dummy))
         with self.assertRaises(exception.StopExtraction):
-            bool(pred(dummy, dummy))
+            pred(dummy, dummy)
 
         pred = util.RangePredicate("")
         with self.assertRaises(exception.StopExtraction):
-            bool(pred(dummy, dummy))
+            pred(dummy, dummy)
 
     def test_unique_predicate(self):
         dummy = None