def netflix_decade_avg (trainingSetDir, w = sys.stdout):
"""
Compute customer averages per decade that the movie was created.
Print to standard out or redirect to file using "> extra/movieDecadeAvgRatings.in"
trainingSetDir is the path to training_set/ from the command line
w is a writer
"""
assert trainingSetDir
movieIDYear = netflix_parse_precomputed('extra/movie_titles_no_nulls.txt', ',')
# Build dict of dict of list {custID: {decade:[totalRating, numRatings]}}
custIDDecade = {}
for file in glob.glob(os.path.join(trainingSetDir, 'mv_*.txt')) :
#print file
with open(file, 'r') as f_myfile:
lines = f_myfile.readlines()
movieID = lines[0].strip(':\r\n')
for custIDRatingDateLine in lines[1:] :
decadeDict = {'1890s':[0, 0],'1900s':[0, 0],'1910s':[0, 0],'1920s':[0, 0],'1930s':[0, 0],'1940s':[0, 0],'1950s':[0, 0],'1960s':[0, 0],'1970s':[0, 0],'1980s':[0, 0],'1990s':[0, 0],'2000s':[0, 0]}
#get custID and actual rating
custIDRatingDateList = custIDRatingDateLine.strip().split(',')
custID = custIDRatingDateList[0]
rating = float(custIDRatingDateList[1])
assert 1.0 <= rating <= 5.0
# Initialize dictionary
if not custID in custIDDecade:
custIDDecade[custID] = decadeDict
else : # custID entry already exists, so add to that dict
decadeDict = custIDDecade[custID]
#look up year
year = movieIDYear[movieID]
#determine the decade
decade = netflix_decade_calc(year)
#add to that decade's [totalRating, numRatings]
totalRatingNumRatingList = decadeDict[decade]
totalRatingNumRatingList[0] += rating #totalRating
totalRatingNumRatingList[1] += 1 #numRatings
decadeDict[decade] = totalRatingNumRatingList
custIDDecade[custID] = decadeDict
# compute averages for each decade
for custID, decadeDict in sorted(custIDDecade.items()) :
w.write( custID + ":\n" )
for decade, totalRatingNumRatingList in sorted(decadeDict.items()) :
totalRating = totalRatingNumRatingList[0]
if totalRating == 0 : #customer didn't rate any movies of that decade
continue
numRating = totalRatingNumRatingList[1]
avgRating = totalRating / numRating
w.write( decade + "=" + str(avgRating) + "\n")
def test_decade2(self):
year = '2005'
self.assert_(netflix_decade_calc(year) == '2000s')
def test_decade3(self):
year = '1989'
self.assert_(netflix_decade_calc(year) == '1980s')
def test_decade(self):
year = '1890'
self.assert_(netflix_decade_calc(year) == '1890s')
