Add find_keys

snippets/find_keys.md

@@ -0,0 +1,22 @@
+---
+title: find_keys
+tags: dictionary,intermediate
+---
+
+Returns all keys in the provided dictionary that have the given value.
+
+Use `dictionary.items()`, a generator and `list()` to return all keys that have a value equal to `val`.
+
+```py
+def find_keys(dict, val):
+  return list(key for key, value in dict.items() if value == val)
+```
+
+```py
+ages = {
+  "Peter": 10,
+  "Isabel": 11,
+  "Anna": 10,
+}
+find_keys(ages, 10) # [ "Peter", "Anna" ]
+```