What is KeyError in Python

In this article, we will see what is a KeyError in Python

The Python compiler throws a KeyError when the key used for a search does not exist in the mapping. A map is a data structure in Python that maps a collection of values onto another collection of values. Dictionary is the most common mapping.

The given below code when executed will throw a KeyError.

#a dictionary to store names and phone numbers

sample_dict = {"Alan" : "99898", "Deva" : "32123", "Ann" : "21345"}

print(sample_dict["Adil"])

Output:

Traceback (most recent call last):
  File "C:\Users\user\Desktop\test.py", line 6, in <module>
    print(sample_dict["Adil"])
KeyError: 'Adil'

The output throws a KeyError because there is no key in the above declared dictionary.

We can use try-except block for handling this exception

#a dictionary to store names and phone numbers

sample_dict = {"Alan" : "99898", "Deva" : "32123", "Ann" : "21345"}
try:
	print(sample_dict["Adil"])
except:
	print("The provided key is not present in the sample_dict")