Add none snippet

snippets/none.md

@@ -0,0 +1,22 @@
+---
+title: none
+tags: list,function,intermediate
+---
+
+Returns `False` if the provided function returns `True` for at least one element in the list, `True` otherwise.
+
+Iterate over the elements of the list to test if every element in the list returns `False` based on `fn`.
+Omit the seconds argument, `fn`, to check if all elements are `False`.
+
+```py
+def none(lst, fn=lambda x: not not x):
+  for el in lst:
+    if fn(el):
+      return False
+  return True
+```
+
+```py
+none([0, 1, 2, 0], lambda x: x >= 2 ) # False
+none([0, 0, 0]) # True
+```