Data commit

Task/Range-extraction/Python/range-extraction-2.py

@@ -0,0 +1,49 @@
+def range_extract(iterable):
+    '''Assumes iterable is sorted sequentially. Returns iterator of range tuples.'''
+    it = iter(iterable)
+
+    try:
+        i = next(it)
+    except StopIteration:
+        return
+
+    while True:
+        low = i
+
+        try:
+            j = next(it)
+        except StopIteration:
+            yield (low, )
+            return
+        while i + 1 == j:
+            i_next = j
+            try:
+                j = next(it)
+            except StopIteration:
+                yield (low, j)
+                return
+            i = i_next
+
+        hi = i
+
+        if   hi - low >= 2:
+            yield (low, hi)
+        elif hi - low == 1:
+            yield (low,)
+            yield (hi,)
+        else:
+            yield (low,)
+
+        i = j
+
+def printr(ranges):
+    print( ','.join( (('%i-%i' % r) if len(r) == 2 else '%i' % r)
+                     for r in ranges ) )
+
+if __name__ == '__main__':
+    for lst in [[-8, -7, -6, -3, -2, -1, 0, 1, 3, 4, 5, 7,
+                 8, 9, 10, 11, 14, 15, 17, 18, 19, 20],
+                [0, 1, 2, 4, 6, 7, 8, 11, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22,
+                 23, 24, 25, 27, 28, 29, 30, 31, 32, 33, 35, 36, 37, 38, 39]]:
+        #print(list(range_extract(lst)))
+        printr(range_extract(lst))