Educational goals of this lab - verify that every student can

• use list subscripts
• use string functions and methods
• use external files for input
• use the in membership operator
• use if statements and loops

INSTRUCTIONS:

(80 points) Team Problem: Done during lab on Monday April 26

• Spellchecking can be done very simply. One file is provided as a "dictionary", which means all the words in it are spelled correctly. The file to be spellchecked has to be broken into individual words and compared to the words in the dictionary file. If the word to be checked is not found in the dictionary, it is misspelled. Only words longer than 3 characters are checked.

  Yes, true spellchecking is much more complicated. How does the program figure out what word is probably what you meant and offer alternatives? How can the search be sped up? since it is what takes most of the time of checking. How can different forms of the same word (plurals, past tenses) be handled efficiently in the dictionary instead of just listing them all? You don't have to deal with any of these!

  Sample runs: Example dictionary.txt

  shark ocean teeth the
  building door       window
  people
  
  through
  from
  away
  

  Example story1.txt

  A shark was chasing a fish through the ocean
  The ocean was next to a building
  The people ran away from the shark
  

• Example run

  Enter a filename to check: story1.txt
  Misspelled words:
  chasing
  fish
  next
  There were 3 misspelled words.
  

• (10 points) Test Cases
  • Get the points by passing the test cases when we test your program.
  • Test cases for get_dictionary()

    Description	Input (dictionary.txt file comma is newline)	Expected Output (return)
    Dictionary with one word per line	angle, right, triangle, leg, longer, square	['angle','right','triangle','leg','longer','square']
    Dictionary with multiple words per line	castle tower, dragon knight sword, with	['castle','tower','dragon','knight','sword','with']
    Dictionary that is empty	just a blank line	[]

  • Test cases for main()

    Description	Input (dictionary.txt, story.txt file)	Expected Output (return)
    Multiple misspelled words (one upper case)	angle, right, triangle, side, longer, square Each leg of a right triangle is shorter than the hypotenuse	Misspelled words: each, shorter, than, hypotenuse, There were 4 misspelled words.
    One misspelled word	castle tower, dragon knight sword, with The knight ran after the dragon	Misspelled words: after, There were 1 misspelled words.
    Empty dictionary, story file not empty	just a blank line green eggs and ham	Misspelled words: green, eggs, There were 2 misspelled words.
    No misspelled words	four, guys, lived, town, small Four guys lived in a small town	There were 0 misspelled words.

  (15 points) Design

  • Documentation as usual: 3 P's for BOTH functions, and a comment for your control structures.
  • Design for a simple spellchecker (NOT COMPLETE!)

    main function
        get the dictionary file (call the function below) 
        ask the user for the filename to spell check
        open it
        turn the words in the file into a list of strings, one word per string 
        close it
        for all the words in that list of words
               force the word to be lowercase
               if the word is more than 3 characters long and 
                            is not in the dictionary list
                    report it as misspelled and count it
        report the count of misspelled words
    ----------------------------------------
    function get the dictionary file
    preconditions - nothing
    postconditions - returns the list of good words from dictionary file
     
       assume dictionary file is called "dictionary.txt"
       open dictionary file
       read the file into one string
       split the string into words in a list (goodlist)
       close dictionary file
       return goodlist  
    -----------------------------------------
    

  (55 points) Implement this program.

  • You can assume that the words in both files are delimited by whitespace.
  • You can assume the files will open correctly.
  • You can assume the dictionary.txt file is all lowercase letters.
  • Test it with the test cases above.
• Submit your finished program with the Canvas link.