handle key doesn't exists in dictionary in python code example

Example 1: python how to check if a dictionary key exists

if word in data:
  return data[word]
else:
  return "The word doesn't exist. Please double check it."

Example 2: add key if not exists python

# credit to Stack Overflow user in the source link
# d is your dictionary

if key not in d:
    d[key] = value