78 lines
2.2 KiB
Python
78 lines
2.2 KiB
Python
#!/usr/bin/env python
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import sys, re, operator, string, inspect
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# Reusing the defensive style program to illustrate this
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#
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# The functions
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#
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def extract_words(path_to_file):
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"""
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Takes a path to a file and returns the non-stop
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words, after properly removing nonalphanumeric chars
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and normalizing for lower case
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"""
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fail = False
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word_list = []
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if type(path_to_file) is str and path_to_file:
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try:
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with open(path_to_file) as f:
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str_data = f.read()
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except IOError as e:
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print "I/O error({0}) when opening {1}: {2}".format(e.errno, path_to_file, e.strerror)
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fail = True
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if not fail:
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pattern = re.compile('[\W_]+')
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word_list = pattern.sub(' ', str_data).lower().split()
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try:
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with open('../stop_words.txt') as f:
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stop_words = f.read().split(',')
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except IOError as e:
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print "I/O error({0}) when opening ../stops_words.txt: {1}".format(e.errno, e.strerror)
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fail = True
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if not fail:
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stop_words.extend(list(string.ascii_lowercase))
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return [w for w in word_list if not w in stop_words] if not fail else []
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def frequencies(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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if type(word_list) is list and word_list <> []:
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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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else:
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return {}
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def sort(word_freq):
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"""
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Takes a dictionary of words and their frequencies
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and returns a list of pairs where the entries are
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sorted by frequency
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"""
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if type(word_freq) is dict and word_freq <> {}:
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return sorted(word_freq.iteritems(), key=operator.itemgetter(1), reverse=True)
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else:
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return []
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#
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# The main function
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#
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filename = sys.argv[1] if len(sys.argv) > 1 else "../input.txt"
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word_freqs = sort(frequencies(extract_words(filename)))
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for tf in word_freqs[0:25]:
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print tf[0], ' - ', tf[1]
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