Python/Ten most reviewed books in the Book Crossing Dataset

def unescape(s):
    s = s.replace("&lt;", "<")
    s = s.replace("&gt;", ">")
    # this has to be last:
    s = s.replace("&amp;", "&")
    return s

# {bookId: {userId: rating,...
dic = {}
fin = open('/root/Downloads/bx/BX-Dump/BX-Book-Ratings.csv')
for line in fin:
    book1 = unescape(line.strip())
    book = book1.split('";"')
    if book[1].strip('"') not in dic:
        dic[book[1].strip('"')] = {}
        dic[book[1].strip('"')][book[0].strip('"')] = book[2].strip('"')
    else:
        dic[book[1].strip('"')][book[0].strip('"')] = book[2].strip('"')


#  {Number of reviews: bookId
dic1 = {}
for a in dic:
    b = len(dic[str(a)])
    try:
        if b not in dic1:
           dic1[b] = [a]
        else: dic1[b].append(a)
    except:
        pass

# [number of reviews,...
popularbooks = dic1.keys()
popularbooks.sort()
popularbooks.reverse()

# {bookId: title
dic2 = {}
fin = open('/root/Downloads/bx/BX-Dump/BX-Books.csv')
for line in fin:
    book1 = unescape(line.strip())
    book = book1.split('";"')
    dic2[book[0].strip('"')] = book[1].strip('"')

# {userId: age,...
useragedic = {}
fin = open('/root/Downloads/bx/BX-Dump/BX-Users.csv')
for line in fin:
    frogs = line.replace('"','').strip().split(";")
    if frogs[0] not in useragedic:
        try:
            useragedic[frogs[0]]  = int(frogs[2])
        except:
            useragedic[frogs[0]]  = int(0)

count = 0
total = 0
print "\n---------------------------------------------\n"
for a in popularbooks:
    for b in dic1[a]:
        if count == 70:
            continue
        else:
            try:
                print a,"Reviews\nBookTitle:", dic2[str(b)],"\nBookId:", str(b)
                count += 1
                count1 = 0
                total = 0
                for c in dic[str(b)]:
                    # skip if user age is unspecified
                    if useragedic[c] == 0:
                        pass
                    else:
                        total += int(useragedic[c])
                        count1 += 1
                avageofrev = float(total/count1)
                print "Average age of reviewer =",avageofrev,"\n\n"
            except:
                print "error with value",str(b),"\n"


""" find the ten most popular books to review

reviews      title
2502      Wild Animus
1295      The Lovely Bones: A Novel
883       The Da Vinci Code
732       Divine Secrets of the Ya-Ya Sisterhood: A Novel
723       The Red Tent (Bestselling Backlist)
647       A Painted House
639 error with value 0679781587
615       The Secret Life of Bees
614       Snow Falling on Cedars
586       Angels & Demons
585       Where the Heart Is (Oprah's Book Club (Paperback))

concerning '639 error with value 0679781587'
>>>for a in dic2:
>>>   if '79587' in a: print a
0674795873
0915795876
0840795874
0671795872

conclusion :
    0679781587 is a value in    BX-Book-Ratings.csv
       that doesnt appear in    BX-Books.csv

"""