Hello, I am having troubles solving this python problem. Any ideas on how to complete this task?

3. A standard letterumber mapping for telephones is DEF 1 23 456 789 1011 # GHI JKL MNO PORS TUV XYZ Write a function 'getNumber(alphabet)', that returns a number, given an uppercase letter. Write a python program that prompts the user to enter a phone number as a string. The input number may contain letters. The program translates a letter (uppercase or lowercase) to a digit and leaves all digits in their places