Question

Q1- say a letter in a word is missing, can you find the missing letter? For example, let the word be 'bas', then the original word could have been 'bias', 'bass', or even some other words. Use the same word list as assignment 7 (https://www.mit.edu/~ecprice/wordlist.10000 (Links to an external site.)) to find the original words. Same code to generate the word list in Python.

import pandas
a = pandas.read_fwf('https://www.mit.edu/~ecprice/wordlist.10000',header=None,names=['w'])
wordlist = a['w'].tolist()

Q (a) -- Suppose we know the index where a letter is missing, write a function findOrigWords(word, index) to return a list of all possible original words. If there doesn't exist such a word, or if the index is invalid, then return the empty list. For example, findOrigWords('bas', 3) searches for a word 'bas_', and will return ['base', 'bass']. Similarly, findOrigWords('bas', 0) searches for '_bas', findOrigWords('bas', 1) searches for 'b_as', findOrigWords('bas', 2) searches for 'ba_s', and findOrigWords('bas', -1) or findOrigWords('bas',4) will return empty list [].

Q(b) - Write a function countOrigWords(word) to return a dictionary, where keys are all possible indices to insert the missing letter, and values are the counts of the completed words. For example, countOrigWords('bas') will return {1:2, 2:3, 3:2}, which means in the word list there are no words in format '_bas', 2 words in format 'b_as', 3 words in format 'ba_s', and 2 words in format 'bas_'. Note: all the values should be positive integers. If a count is 0, then the corresponding index should be removed out of the dictionary.

(python)

Answer 1

Here is the completed code for this problem. Comments are included, go through it, learn how things work and let me know if you have any doubts or if you need anything to change. If you are satisfied with the solution, please rate the answer. Thanks

Note: Please maintain proper code spacing (indentation), just copy the code part and paste it in your compiler/IDE directly, no modifications required.

#code

import pandas

# from the url, loading the words to a list
a = pandas.read_fwf('https://www.mit.edu/~ecprice/wordlist.10000', header=None, names=['w'])
wordlist = a['w'].tolist()


'''required method to generate a list of possible words where a letter is added at
   specified index.
'''
def findOrigWords(word, index):
    # if index is invalid, returning empty list
    if index < 0 or index > len(word):
        return []
    # converting word to lower to minimize comparisons
    word = word.lower()
    # getting string before index
    pre = word[:index]
    # getting string after index
    post = word[index:]
    # creating an empty list
    result = []
    # looping through each possible alphabet, once
    for c in 'abcdefghijklmnopqrstuvwxyz':
        # adding c between pre and post
        combined = pre + c + post
        # checking if this word is in wordlist
        if combined in wordlist:
            # appending combined to result
            result.append(combined)
    # returning result
    return result



''' method to return a dictionary, where keys are all possible indices to insert the 
    missing letter, and values are the counts of the completed words 
'''
def countOrigWords(word):
    #creating a dict
    result = dict()
    #looping from 0 to len(word)
    for i in range(len(word) + 1):
        #finding possible words when a character is inserted at index i
        possible_words = findOrigWords(word, i)
        #if returned list is not empty, adding to result dict with key being i and 
        #value being the length of possible_words list
        if len(possible_words) > 0:
            result[i] = len(possible_words)
    return result


#testing
print(findOrigWords('bas', 0)) # []
print(findOrigWords('bas', 1)) # ['bias', 'bras']
print(findOrigWords('bas', 2)) # ['bags', 'bars', 'bass']
print(findOrigWords('bas', 3)) # ['base', 'bass']
print(findOrigWords('bas', 4)) # []
print(countOrigWords('bas')) # {1: 2, 2: 3, 3: 2}