how to check if a key is not in a dictionary python code example

Example 1: python check if key exists

# You can use 'in' on a dictionary to check if a key exists
d = {"key1": 10, "key2": 23}
"key1" in d
# Output:
# True

Example 2: how to know if a key is in a dictionary python

dict = {"key1": 1, "key2": 2}

if "key1" in dict: