update from Atlas

14-it-generator/aritprog_v3.py

@@ -0,0 +1,11 @@
+# BEGIN ARITPROG_ITERTOOLS
+import itertools
+
+
+def aritprog_gen(begin, step, end=None):
+    first = type(begin + step)(begin)
+    ap_gen = itertools.count(first, step)
+    if end is not None:
+        ap_gen = itertools.takewhile(lambda n: n < end, ap_gen)
+    return ap_gen
+# END ARITPROG_ITERTOOLS