Step 1

Write a small database for your personal contacts.

Each contact should be represented by a single object1 that can hold information about name, date of birth, phone number and mail address.2

Store your contacts in an appropriate data structure. 3

Step 2

Wouldn’t it be great if you could simply print your contacts by just calling print() with the identifier of the contact object?

Add a __str__ method4 in your class to make it possible.

Step 3

Imagine one of your contacts get a new mailadress.

Add functions to your class that make you able to change the mail address or phone number of a contact (for practising purposes one function is enough).5

Step 4

Now splice your mail/phone number changer function with some I/O.

Use string formatting to ask the user for the new information while displaying the old.6

  1. You could write a class Contact() to instantiate objects from it. ↩

  2. Hand over this information to the __init__ function and store them in instance variables. ↩

  3. You might want to use a dict or a list. ↩

  4. Don’t forget the self argument… ↩

  5. Keep it simple! Call the function from an object with e.g. identifier.changeMail("xy@z.com") and replace the address stored in the instance. ↩

  6. You need the str.format() function here. You can nest it inside of an input() function. ↩