python related word search and replace with list words

Question

Consider this, I have a list; list1=['car', 'bike', 'van', 'class'], and I am parsing a text file. This text file can contain other arbitrary words that are not in this list and are not misspellings of words in this list.

• If 'ca' is in the file, my algorithm would replace it with 'car'

• If the file contains 'bke' it is replaced with 'bike'

• If the file contains 'clss', it is replaced with 'class'

My algorithm is basically an error correction algorithm. How do I replace the relevant misspelled words with the words in the list?

Any answer to the question will be appreciated!

Answer 1

Using a levenshtein algorithm, you can do this:

tgt_list='ca bke clss'.split()    
for word in ['car','bike','van','class']:
    wdist_exp=((w, levenshtein(w, word)) for w in tgt_list)
    closest, dist=min(wdist_exp, key=lambda t: t[1])
    print '{}=>{}   ld={}'.format(closest,word,dist) 

Prints:

ca=>car   ld=1
bke=>bike   ld=1
ca=>van   ld=2
clss=>class   ld=1

It is also possible with the regex module:

import regex    

template='{}=>{} with {} substitutions, {} insertions, {} deletions'
tgt='ca bke clss'
for word in ['car','bike','van','class']:
    pat=r'((?:\b{}\b){{e<=2}})'.format(word)
    m=regex.search(pat, tgt, regex.BESTMATCH)     
    if m:
        print template.format(m.group(1),word,*m.fuzzy_counts)

Prints:

ca =>car with 1 substitutions, 0 insertions, 0 deletions
bke=>bike with 0 substitutions, 0 insertions, 1 deletions
ca =>van with 2 substitutions, 0 insertions, 0 deletions
clss=>class with 0 substitutions, 0 insertions, 1 deletions

You might want to investigate Python's difflib module with a similar approach used here.