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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.