Python - Finding word frequencies of list of words in text file

collections.Counter() has this covered if I understand your problem.

The example from the docs would seem to match your problem.

# Tally occurrences of words in a list
cnt = Counter()
for word in ['red', 'blue', 'red', 'green', 'blue', 'blue']:
    cnt[word] += 1
print cnt


# Find the ten most common words in Hamlet
import re
words = re.findall('\w+', open('hamlet.txt').read().lower())
Counter(words).most_common(10)

From the example above you should be able to do:

import re
import collections
words = re.findall('\w+', open('1976.03.txt').read().lower())
print collections.Counter(words)

EDIT naive approach to show one way.

wanted = "fish chips steak"
cnt = Counter()
words = re.findall('\w+', open('1976.03.txt').read().lower())
for word in words:
    if word in wanted:
        cnt[word] += 1
print cnt

One possible implementation (using Counter)...

Instead of printing the output, I think it would be simpler to write to a csv file and import that into Excel. Look at http://docs.python.org/2/library/csv.html and replace print_summary.

import os
from collections import Counter
import glob

def word_frequency(fileobj, words):
    """Build a Counter of specified words in fileobj"""
    # initialise the counter to 0 for each word
    ct = Counter(dict((w, 0) for w in words))
    file_words = (word for line in fileobj for word in line.split())
    filtered_words = (word for word in file_words if word in words)
    return Counter(filtered_words)


def count_words_in_dir(dirpath, words, action=None):
    """For each .txt file in a dir, count the specified words"""
    for filepath in glob.iglob(os.path.join(dirpath, '*.txt')):
        with open(filepath) as f:
            ct = word_frequency(f, words)
            if action:
                action(filepath, ct)


def print_summary(filepath, ct):
    words = sorted(ct.keys())
    counts = [str(ct[k]) for k in words]
    print('{0}\n{1}\n{2}\n\n'.format(
        filepath,
        ', '.join(words),
        ', '.join(counts)))


words = set(['inflation', 'jobs', 'output'])
count_words_in_dir('./', words, action=print_summary)