finished toolbox, attempted to learn lambda functions and list compre…

frequency.py

@@ -4,21 +4,65 @@
 import string
 
 def get_word_list(file_name):
-	""" Reads the specified project Gutenberg book.  Header comments,
-		punctuation, and whitespace are stripped away.  The function
-		returns a list of the words used in the book as a list.
-		All words are converted to lower case.
-	"""
-	pass
+    """ Reads the specified project Gutenberg book.  Header comments,
+	punctuation, and whitespace are stripped away.  The function
+	returns a list of the words used in the book as a list.
+	All words are converted to lower case.
+    """
+    #open and read file
+    f = open(file_name, 'r')
+    text = f.read()
+
+    #create word list which we will return
+    word_list = []
+
+    #make lowercase
+    text = string.lower(text)
+
+    #replace punctuation with spaces
+    for char in string.punctuation:
+        text = string.replace(text, char, ' ')
+
+    for line in text.split('\n'):
+        for word in line.split(' '):
+            word_list.append(word)
+
+    #don't include lines with only empty or \r
+    word_list = [x for x in word_list if x != '']
+    word_list = [x for x in word_list if x != '\n']
+    word_list = [x for x in word_list if x != '\r']
+
+    return word_list
+
 
 def get_top_n_words(word_list, n):
-	""" Takes a list of words as input and returns a list of the n most frequently
-		occurring words ordered from most to least frequently occurring.
-
-		word_list: a list of words (assumed to all be in lower case with no
-					punctuation
-		n: the number of words to return
-		returns: a list of n most frequently occurring words ordered from most
-				 frequently to least frequentlyoccurring
-	"""
-	pass
+    """ Takes a list of words as input and returns a list of the n most frequently
+	occurring words ordered from most to least frequently occurring.
+
+	word_list: a list of words (assumed to all be in lower case with no punctuation
+	n: the number of words to return
+	returns: a list of n most frequently occurring words ordered from most
+	frequently to least frequentlyoccurring
+    """
+    histogram = []
+
+    for uniq in set(word_list):
+        counter = 0
+        for word in word_list:
+            if uniq == word:
+                counter += 1
+        histogram.append((uniq, counter))
+    histogram.sort(key=lambda tup: tup[1], reverse=True)
+    return histogram[0:n]
+
+
+
+file = 'pg4908.txt'
+
+word_list =  get_word_list(file)
+top_words = get_top_n_words(word_list, 20)
+
+for item in top_words:
+    print 'word = {}, number of times = {}'.format(item[0], item[1])
+#it appears that something is going wrong with the text parsing.  I get some sort of space
+#or new line in the histogram.