30-seconds-of-code/snippets/python/s/find-key.md

title, type, language, tags, cover, dateModified

title	type	language	tags	cover	dateModified
Find key of value	snippet	python	dictionary	blue-red-mountain	2020-11-02T19:27:53+02:00

Finds the first key in the provided dictionary that has the given value.

• Use dictionary.items() and next() to return the first key that has a value equal to val.

def find_key(dict, val):
  return next(key for key, value in dict.items() if value == val)

ages = {
  'Peter': 10,
  'Isabel': 11,
  'Anna': 9,
}
find_key(ages, 11) # 'Isabel'