Python Program for Soundex Algorithm

This is a python implementation for Soundex Algorithm.

This Program builds a JSON document as a dictionary and is kept on building at every execution. Its constantly appended and referenced while the program  is executed.

Program:

from re import sub
def remove_symbols(input_string):
    #Convert the characters to lower case and then use
    #Regular expressions to remove non a-z chars
    return sub('[^A-Z]+', '', input_string)

def clean(input_string):
    #Convert the characters to lower case and then use
    #Regular expressions to remove non a-z chars
    return sub('[^a-z]+', '', input_string.lower())

word = "Input"

def soundex(word):
    #Step 1: Capitalize all letters in the word and drop all punctuation marks.
    word = remove_symbols(word.upper())
    
    #Step 2: Retain the first letter of the word. 
    first_letter = word[0]
    word = word[1:]
    
    #Step 3 & 4: Change ( 'A', E', 'I', 'O', 'U', 'H', 'W', 'Y') to 0
    #And ('B','F','P','V') => 1
    #('C','G','J','K','Q','S','X','Z') => 2
    #('D,'T') => 3 , ('L') =. 4 , ('M','N') => 5 and ('R') => 6  
    pre = ['[AEIOUWHY]','[BFPV]','[CGJKQSXZ]','[DT]','[L]','[MN]','[R]']
    post= ['0','1','2','3','4','5','6']
    for find , replace in zip(pre, post):
        word = sub(find, replace, word)
    
    #Step 5: Remove all pairs of digits which occur beside each other from the string that resulted after Step 4.
    new_word = ""
    maxpos = len(word) - 1
    for i in range(maxpos+1):
        if i< maxpos and word[i] != word[i+1]:
            new_word += word[i]
        elif i == maxpos and word[i] != word[i-1]:
            new_word += word[i]
            
    #Step 6: Remove all zeros from the string that results from step 5.0 (placed there in step 3)
    #(Retaining the first character as well) 
    word = first_letter + sub('0','', new_word)
    
    #Step 7:  Pad the string that reVeekramsulted from step (6) with trailing zeros and return only the first four positions,
    #which will be of the form <uppercase letter> <digit> <digit> <digit>
    length = len(word)
    if length >= 4:
        word = word[:4]
    else:
        word = word + ("0" * (4 - length))
        
    #print input, word
    return word

import json
fp = open("D:\\Vikram Projects\\Eclipse Workspace\\Soundex Algorithm\\repository.txt")
dic  = json.load(fp)
#dic = dic[0]
fp.close()

from os import listdir, path 
dict = {}
files = []
for fle in listdir("data"):
    #Ignore the ~ and . i.e. hidden / system files
    f = open(path.join("data", fle)) 
    if fle.startswith('~') or fle.startswith('.'): continue
    dict[fle] = list()
    for line in f.readlines():
        dict[fle] += map(clean, line.split())
    files.append(fle)     

word = raw_input("Enter a word: ").lower()
code = soundex(word)

if dic.has_key(code):
    print word+" has  following similar words: "
    print dic[code]
else:
    print word + " has no phonetically similar words."
    dic[code] = list()

try:       
    _ = dic[code].index(word)
except(ValueError):
    dic[code].append(word)

print "And it's present in following files: "
for fle in files:
    for word in dic[code]:
        try:
            if dict[fle].index(str(word)) != -1:
                print word +" is found in --> " + fle
                continue
        except (ValueError):
            pass
#insert further into dictionary

    #dic[code].add()
    
fp = open("repository.txt",'w')
json.dump(dic, fp)

------------------------------------------------------------------------------

Repository.txt

{

"C416": ["calpurnia", "calpoornia","calpornia"],

"V265": ["vikrant","vikramjeet", "veekram", "vikram"],
"A123": ["abheejit"], "V220": ["vishakha"],
"M622": ["markus", "markoos","merkus"],

"J310": ["jaydeep","jaydip"],

"V240": ["vishal"], 

"V625": ["virkam"],

"V230": ["viksto"],

"B632": ["brutus", "brutoos"]

}



Input Files:
 
F1.txt 
 
Brutus killed calpurnia, brutoos the evil brother of calpornia,
avenged her death. vikram gets angry when called veekram. 
 
F2.txt


Markus is the
step brother of brutus. Brutus and markus
are each others good friends. calpoornia,
is also a friend.

Vikram is a friend of Markus.
 
 
F3.txt


brutus and markus were classmates but they changed roads
after college. They do not have any similar interests now. brutoos is 
a butcher and merkus weaves. 




veekram and markus were also 




classmates but they rarely spoke.
 
 

Ouptut

Enter a word: merkus


merkus has  following similar words:  




[u'markus', u'markoos']

And it's present in following files: 


markus is found in --> f2.txt


markus is found in --> f3.txt


merkus is found in --> f3.txt

      ---------------------------------------------------------------------

Enter a word: vikram


vikram has  following similar words: 


[u'vikrant', u'vikramjeet',
u'veekram', u'vikram']

And it's present in following files: 

veekram is found in --> f1.txt


vikram is found in --> f1.txt


vikram is found in --> f2.txt


veekram is found in --> f3.txt

---------------------------------------------------------------------
      Enter a word: santiago


santiago has no phonetically similar
words.

And it's present in following files: