example.py

d = {}

with open("dictfile.txt") as f:
    d.update([map(str.strip, line.split("=")) for line in f])
    # alternatively:
    # for line in f:
    #     k, v = line.split('=')
    #     d[k.strip()] = v.strip()

with open("wordfile.txt") as f:
    for line in f:
        words = filter(None, [str(d.get(word, '')) for word in line])  # the cast to str is actually unnecessary here
        # alternatively:
        # words = []
        # for word in line:
        #     words.append(str(d.get(word, '')))
        # words = filter(None, words)
        print(", ".join(words))