Alphabet position in python

Question

Newbie here...Trying to write a function that takes a string and replaces all the characters with their respective dictionary values. Here is what I have:

def alphabet_position(text):

    dict = {'a':'1','b':'2','c':'3','d':'4','e':'5','f':'6','g':'7','h':'8':'i':'9','j':'10','k':'11','l':'12','m':'13','n':'14','o':'15','p':'16','q':'17','r':'18','s':'19','t':'20','u':'21','v':'22','w':'23','x':'24','y':'25','z':'26'}
    text = text.lower()
    for i in text:
        if i in dict:
            new_text = text.replace(i, dict[i])
    print (new_text)

But when I run:

alphabet_position("The sunset sets at twelve o' clock.")

I get:

the sunset sets at twelve o' cloc11.

meaning it only changes the last character in the string. Any ideas? Any input is greatly appreciated.

Answer 1

Following your logic you need to create a new_text string and then iteratively replace its letters. With your code, you are only replacing one letter at a time, then start from scratch with your original string:

def alphabet_position(text):

    dict = {'a':'1','b':'2','c':'3','d':'4','e':'5','f':'6','g':'7','h':'8','i':'9','j':'10','k':'11','l':'12','m':'13','n':'14','o':'15','p':'16','q':'17','r':'18','s':'19','t':'20','u':'21','v':'22','w':'23','x':'24','y':'25','z':'26'}
    new_text = text.lower()
    for i in new_text:
        if i in dict:
            new_text = new_text.replace(i, dict[i])
    print (new_text)

And as suggested by Kevin, you can optimize a bit using set. (adding his comment here since he deleted it: for i in set(new_text):) Note that this might be beneficial only for large inputs though...

Answer 2

As your question is generally asking about "Alphabet position in python", I thought I could complement the already accepted answer with a different approach. You can take advantage of Python's string lib, char to int conversion and list comprehension to do the following:

import string


def alphabet_position(text):
    alphabet = string.ascii_lowercase
    return ''.join([str(ord(char)-96) if char in alphabet else char for char in text])