A variation on /u/StonedEmu's text compression program to introduce him to a few slightly advanced python concepts.

IndexAndCompress.py

_text = 'raw.txt'
_index = 'index.txt'

def readFile(F):
    '''Pretty generic 'read' operation'''
    data = []
    with open(F, 'r') as f:
        for line in f:
            data.append(line.strip())
    return data

def update_index(ind, F, txt):
    '''Updates word index in memory and hard file with new words in text.'''
    words = set()
    for row in txt:
        words.update(row.split())
    words.difference_update(index)
    if words:
        with open(F,'ab') as f:
            for w in words:
                f.write(w+'\n')
                ind.append(w)
    return ind
                
index = readFile(_index)
text = readFile(_text)
index = update_index(index, _index, text)

for row in text:
    tokens = row.split()
    compressed = [chr(i+200) for word in tokens for i,w in enumerate(index) if w == word]
    print compressed