Add cumsum

snippets/cumsum.md

@@ -0,0 +1,20 @@
+---
+title: cumsum
+tags: list,intermediate
+---
+
+Creates a list of partial sums.
+
+- Use `itertools.accumulate()` to create the accumulated sum for each element.
+- Use `list()` to convert the result into a list.
+
+```py
+from itertools import accumulate
+
+def cumsum(lst):
+  return list(accumulate(lst))
+```
+
+```py
+cumsum(range(0, 15, 3)) # [0, 3, 9, 18, 30]
+```