updated from Atlas

attic/iterables/aritprog_v4.py

@@ -0,0 +1,14 @@
+# BEGIN ARITPROG_ITERTOOLS
+import itertools
+
+
+def aritprog_gen(begin, step, end=None):
+    if end is not None and begin >= end:
+        return
+    yield type(begin + step)(begin)
+    tail_gen = itertools.count(begin+step, step)
+    if end is not None:
+        tail_gen = itertools.takewhile(lambda n: n < end, tail_gen)
+    for x in tail_gen:
+        yield x
+# END ARITPROG_ITERTOOLS

attic/iterables/aritprog_v5.py

@@ -0,0 +1,13 @@
+# BEGIN ARITPROG_ITERTOOLS
+import itertools
+
+
+def aritprog_gen(begin, step, end=None):
+    if end is not None and begin >= end:
+        return
+    yield type(begin + step)(begin)
+    tail_gen = itertools.count(begin+step, step)
+    if end is not None:
+        tail_gen = itertools.takewhile(lambda n: n < end, tail_gen)
+    yield from tail_gen
+# END ARITPROG_ITERTOOLS