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exercises-in-programming-style/06-the-one/tf-06.py
Crista Lopes f393c471bf Added style #6
2013-09-22 10:46:46 -07:00

94 lines
2.3 KiB
Python

import sys, re, operator, string
#
# The monadic class for this example
#
class TFTheOne:
def __init__(self, v):
self._value = v
def bind(self, func):
result = func(self._value)
return TFTheOne(result)
def printm(monad):
print monad._value
#
# The functions
#
def read_file(path_to_file):
"""
Takes a path to a file and returns the entire
contents of the file as a string
"""
f = open(path_to_file)
data = f.read()
f.close()
return data
def filter_chars(str_data):
"""
Takes a string and returns a copy with all nonalphanumeric chars
replaced by white space
"""
pattern = re.compile('[\W_]+')
return pattern.sub(' ', str_data)
def normalize(str_data):
"""
Takes a string and returns a copy with all characters in lower case """
return str_data.lower()
def scan(str_data):
"""
Takes a string and scans for words, returning
a list of words.
"""
return str_data.split()
def remove_stop_words(word_list):
""" Takes a list of words and returns a copy with all stop words removed """
f = open('../stop_words.txt')
stop_words = f.read().split(',')
f.close()
# add single-letter words
stop_words.extend(list(string.ascii_lowercase))
return [w for w in word_list if not w in stop_words]
def frequencies(word_list):
"""
Takes a list of words and returns a dictionary associating
words with frequencies of occurrence
"""
word_freqs = {}
for w in word_list:
if w in word_freqs:
word_freqs[w] += 1
else:
word_freqs[w] = 1
return word_freqs
def sort(word_freq):
"""
Takes a dictionary of words and their frequencies and returns a list
of pairs where the entries are sorted by frequency
"""
return sorted(word_freq.iteritems(), key=operator.itemgetter(1), reverse=True)
def print_freqs(word_freqs):
for tf in word_freqs[0:25]:
print tf[0], ' - ', tf[1]
def top25_freqs(word_freqs):
top25 = ""
for tf in word_freqs[0:25]:
top25 += str(tf[0]) + ' - ' + str(tf[1]) + '\n'
return top25
#
# The main function
#
printm(TFTheOne(sys.argv[1]).bind(read_file).bind(filter_chars).bind(normalize).bind(scan).bind(remove_stop_words).bind(frequencies).bind(sort).bind(top25_freqs))