Dictionary keys

Creates a flat list of all the keys in a flat dictionary.

• Use dict.keys() to return the keys in the given dictionary.
• Return a list() of the previous result.

def keys_only(flat_dict):
  return list(flat_dict.keys())

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