tasks a-s

Task/Range-extraction/Python/range-extraction-1.py

@@ -0,0 +1,19 @@
+def rangeextract(lst):
+    lenlst = len(lst)
+    i, ranges = 0, []
+    while i< lenlst:
+        low = lst[i]
+        while i <lenlst-1 and lst[i]+1 == lst[i+1]: i +=1
+        hi = lst[i]
+        ranges.append(
+            '%i-%i'  % (low, hi) if hi - low >= 2 else
+            ('%i,%i' % (low, hi) if hi - low == 1 else
+             '%i' % low) )
+        i += 1
+    return ','.join(ranges)
+
+lst = [ 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(rangeextract(lst))

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

@@ -0,0 +1,26 @@
+def grouper(lst):
+    src = iter(lst)
+    acc = [ next(src) ]
+    for i in src:
+        if i == acc[-1] + 1: acc.append(i)
+        else:
+            yield acc
+            acc = [i]
+    yield acc
+    raise StopIteration()
+
+def rangegrouper(lst):
+    for g in grouper(lst):
+        if len(g) == 2:
+            # satisfy rule that only runs longer than 2 are grouped
+            a,b = g
+            yield [a]
+            yield [b]
+        else: yield g
+    raise StopIteration()
+
+input= [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(rangegrouper(input)) # print groups
+as_strings= ['%s%s%s' % ((g[0],'-',g[-1]) if len(g) > 1 else (g[0],'','')) for g in rangegrouper(input)]
+print as_strings
+print ', '.join(as_strings)