patterns.txt

buy guitars [location]
buy [brand] guitars [location]
buy [brand] guitars
[brand] guitars for sale
[brand] guitars for sale in [location]
[location] best [brand] guitars

simple_script_POC.py

import csv

phrases = []

with open ('words.csv', 'r')  as wordfile:
    csvreader = csv.DictReader(wordfile, skipinitialspace=True)
    words = [{key: value for key, value in row.items()} for row in csvreader]
    print(words)
    with open('patterns.txt', 'r') as patternfile:
        patterns = patternfile.readlines()
        for pattern in patterns:
            for word in words:
                print(word)
                # Transform the location to [location], brand to [brand]
                word_type = '[{}]'.format(word['type'])
                # Obviously it replaces just the first found token (location or brand)
                if word_type in pattern:
                    phrase = pattern.replace(word_type, word['word'])
                    phrases.append(phrase)

with open('result.txt', 'w') as resultfile:
    for phrase in phrases:
        print(phrase.strip())
        resultfile.write(phrase)

words.csv