Question

I found a suggestion on a Stack Overflow topic about problems beginners should do to learn a new language. A user posted a very nice list of problems from Beginner to advanced that should help you get to know a language. One of the problems is to create a phone book, with random phone numbers and random people on the phone book, and a user should be able to search a phone number and find the person, and vice-versa.

So how do you randomly generate x amount of values and store them, without a database, specifically focusing on Python and Ruby.

Answer 1

You need to define some more parameters before you can tackle this problem.

• Are phone numbers unique to each person?
• How will you store names? First name and last name in different strings? All in one string?
• Do you want to support fuzzy matching?
• do you want to offer reverse lookup functionality? (I.E. look up a person based on a phone number?)

In Python, you could do all of this with sets, lists, and/or dicts, but you might also look into the sqlite3 module.

To generate a random string of letters in Python you do:

import random
import string

minLength = 5 # the minimum length of the string.
maxLength = 15 # the maximum length of the string

randstring = string.join([random.choice(string.lowercase)
    for i in range(random.randrange(minlength,maxlength+1))], '')

To do the same with numbers, just replace random.lowercase with [1,2,3,4,5,6,7,8,9,0]