< Back

Lab 20: Strings

As usual, create a directory to hold today's files. All programs that you write today should be stored in this directory.

$ cd ~/cs120/labs
$ mkdir lab20 
$ cd lab20 


Practice 1

Write a function called compare(string1, string2), which takes two strings as parameters. The function should return True if the two strings are the same, ignoring capitalization and ignoring leading and trailing whitespace, and False otherwise.


Practice 2

Write a function called swap_words(string), which takes a single string as a parameter. Assume that the specified string contains two words separated by exactly one space character. The function should return a new string that swaps the positions of the two words in the specified string.



Pig Latin Translator

Pig Latin is a somewhat silly language parody that is actually entirely English based. It is a simple transposition of letters that gives the effect of a "foreign" sounding language. However, even Thomas Jefferson couldn't resist writing letters to his friends in Pig Latin. The rules for converting an English word to Pig Latin are incredibly easy:

Details

Write a function called convert_to_pig_latin(text) in a file called pig_latin.py. This function takes a string as a parameter, and returns a string which is the pig latin translation of the text parameter.

Make sure your program handles all necessary cases gracefully. What additional test cases should you check?

Sample Test Cases

Function Parameters Expected Output
"scram" am'scray
"immediate" immediateyay

Hint

  • Before converting the input text to Pig Latin, the function must find the index of the first vowel. Finding the index of the first vowel would be easier if there was a function that returned whether a single character is a vowel. So write the function is_vowel(character). The function has one parameter character an alphabetic string of length 1. The function should return True if character is 'a', 'e', 'i', 'o', or 'u' and False otherwise. Test this function before proceeding.

  • Finding the index of the first vowel requires traversing the text and testing whether each character is a vowel. Writing this as a separate function would make writing the translation function easier. So write the function index_of_first_vowel(text) that returns the index of first vowel in the specified text. Since the location of the first vowel is unknown, the number of times the traversal loop will need to run is unknown and so the function will not be able to use a for loop to traverse the string. Instead, the function should use a while loop that increments an index variable every iteration while the character at the index variable is not a vowel.

  • With the above two functions, writing the translation function is simple. If the index of the first vowel is 0, then apply the first Pig Latin rule using concatenation. If the index of the first vowel is not 0, then apply the second Pig Latin rule using a slice and concatenation.

Challenge

Ofyay ourse'cay, ityay akes'may ittle'lay ense'say o'tay ite'wray ayay ogram'pray o'tay anslate'tray ayay ord'way o'tay ig'pay atin'lay ifyay ityay annot'cay anslate'tray ack'bay e'thay otheryay ay'way! Ite'wray ayay unction'fay onvert_from_pig_latin'cay at'thay akes'tay ayay ord'way alreadyyay inyay ig'pay atin'lay, andyay eturns'ray e'thay Englishyay equivalentyay.