Q$1.$ As part of a cryptography assignment, you are required to implement Caesar cipher

algorithms using Python. Follow the instructions provided below to complete the task:

a$.$ Write a Python function called caesar$\_$cipher that takes two inputs: a plaintext message and

an integer key.

b$.$ Implement the Caesar cipher algorithm to encrypt the plaintext message by shifting each

letter by the given key.

c$.$ Ensure that the function retains the case of the letters and preserves spaces and other nonalphabetic characters.

d$.$ Test the caesar$\_$cipher function by encrypting the your full name with a key of $3$