python核心編程第七章習題解答(1)

7-3 (c)根據已按照字母順序排序好的字典的值，顯示出這個字典中的鍵和值

def sortdict(dict1):                             valuelist=dict1.values()                           valuelist.sort()                          dict2={}                          for value in valuelist:                             for key in dict1:                             if dict1[key]==value and key not in dict2:   #防止重複輸出                                          print key,value,                                          dict2[key]=value                          if __name__=="__main__":                             dict1={'c':4,'a':5,'hi':78,'d':5,'r':5}                              sortdict(dict1)

7-5userpw.py

def olduser():    promt="login(case-insensitive):"    while True:        name=raw_input(promt).lower()        nam=set(name)        if nam-valid!=set([]):            promt='invalid char,try another:'            continue        if name not in db.keys():            info=raw_input('New User?(Y/N)').lower()            if info=='y':                pwd=raw_input('passwd:')                db[name]=(md5.new(pwd)).hexdigest()                dbt[name]=time.localtime()                return            else:                promt='invalid user,try another:'                #continue        else:            break    pwd=raw_input('passwd:')    passwd = db.get(name)    if passwd==(md5.new(pwd)).hexdigest():        print 'welcome back %s'%name        last=time.mktime(dbt[name])        now=time.mktime(time.localtime())        if now-last < 3600*4:            lastime=time.strftime("%Y-%m-%d %H:%M:%S", dbt[name])            print "You already logged in at: %s."%lastime        dbt[name]=time.localtime()    else:        print 'login incrrect!'