Tagging sentences with custom defined dictionary

Question

I am trying to tag sentences using a custom defined dictionary. For example if I have two text files (1. My sentences, 2. My dictionary)

Sentences file:

I have abdominal pain and have difficulty breathing

Dictionary file:

Abdominal pain, difficulty breathing

I would like output to be like this:

New file:

I have abdominal pain (AE) and have difficulty breathing (AE)

How can this be done? Please see the following code:

import csv
from difflib import SequenceMatcher as SM
from nltk.util import ngrams

import codecs

with open('dictionary.csv','r') as csvFile:
    reader = csv.reader(csvFile)
    myfile = open("sentences.txt", "rt")
    my3file = open("tagged_sentences.txt", "w")
    hay = myfile.read()
    myfile.close()

phrases = []
for row in reader:
    needle = row[1]
    needle_length = len(needle.split())
    max_sim_val = 0.9
    max_sim_string = u""
    for ngram in ngrams(hay.split(), needle_length + int(.2 * needle_length)):
        hay_ngram = u" ".join(ngram)

        similarity = SM(None, hay_ngram, needle).ratio()
        if similarity > max_sim_val:
            max_sim_val = similarity
            max_sim_string = hay_ngram
            str = [row[1] , ' ', max_sim_val.__str__(),' ', max_sim_string , '\n']
            str1 = max_sim_string , row[2]
            phrases.append((max_sim_string, row[2]))

for line in hay.splitlines():
    if any(max_sim_string in line for max_sim_string, _ in phrases):
        for phrase in phrases:
            max_sim_string, _ = phrase
            if max_sim_string in line:
                tag_sent = line.replace(max_sim_string, phrase.__str__())
                my3file.writelines(tag_sent + '\n')
                print(tag_sent)
                break        
    else:
        my3file.writelines(line + '\n')

csvFile.close()

The above code just creates an empty "tagged_sentences" file Thanks