56 lines
1.7 KiB
Python
56 lines
1.7 KiB
Python
#!/usr/bin/env python
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import sys, re, operator, string
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#
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# Two down-to-earth things that cannot be reflected on
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# without serious performance penalties
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#
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stops = set(open("../stop_words.txt").read().split(",") + list(string.ascii_lowercase))
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def frequencies_imp(word_list):
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"""
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Takes a list of words and returns a dictionary associating
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words with frequencies of occurrence
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"""
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word_freqs = {}
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for w in word_list:
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if w in word_freqs:
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word_freqs[w] += 1
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else:
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word_freqs[w] = 1
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return word_freqs
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#
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# Let's write our function bodies as strings.
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# Because we're looking at them from "above"
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#
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extract_words_func_body = "lambda name : [x.lower() for x in re.split('[^a-zA-Z]+', open(name).read()) if len(x) > 0 and x.lower() not in stops]"
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frequencies_func_body = "lambda word_list : frequencies_imp(word_list)"
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sort_func_body = "lambda word_freq: sorted(word_freq.iteritems(), key=operator.itemgetter(1), reverse=True)"
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#
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# So far, this program isn't much about term-frequency. It's about
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# a bunch of strings that look like function bodies.
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# Let's add our functions to the "base" program, dynamically.
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# We're re-writing this program by adding more functions to it
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# from "above".
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#
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exec('extract_words = ' + extract_words_func_body)
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exec('frequencies = ' + frequencies_func_body)
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exec('sort = ' + sort_func_body)
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#
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# The main function. This would work just fine:
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# word_freqs = sort(frequencies(extract_words(sys.argv[1])))
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# But because we're being introspective, we'll call the
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# functions also from "above"
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#
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word_freqs = locals()['sort'](locals()['frequencies'](locals()['extract_words'](sys.argv[1])))
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for tf in word_freqs[0:25]:
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print tf[0], ' - ', tf[1]
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