Head_first_python Study Notes (iv)

Using dictionaries

#print_detail同之前的print_times>>> import print_detail >>> james2 = print_detail.print_detail(‘james2‘)>>> james2[‘James Lee‘, ‘2002:3:14‘, ‘2:34‘, ‘3:21‘, ‘2:34‘, ‘2:45‘, ‘3:01‘, ‘2:01‘, ‘2:01‘, ‘3:10‘, ‘2:22‘, ‘2:01‘, ‘2:01‘, ‘2:16‘]>>> james2Dic = {}>>> james2Dic[‘name‘] = james2.pop()>>> james2Dic[‘dob‘] = james2.pop()>>> james2Dic[‘times‘] = james2>>> james2Dic{‘dob‘: ‘2:01‘, ‘name‘: ‘2:16‘, ‘times‘: [‘James Lee‘, ‘2002:3:14‘, ‘2:34‘, ‘3:21‘, ‘2:34‘, ‘2:45‘, ‘3:01‘, ‘2:01‘, ‘2:01‘, ‘3:10‘, ‘2:22‘, ‘2:01‘]}

Classes and objects

#类定义方法class classname:    def __init__(self):        #initialize code            ...

• Python requires that the first argument of each method be the calling object instance (self)

Simple test Code:

>>> class Athlete:...     def __init__(self,name,dob=None,times=[]):...             self.name = name...             self.dob = dob...             self.times = times... >>> type(Athlete)<type ‘classobj‘>>>> sarah = Athlete(‘sarah Sweeney‘,‘2002-02-22‘,[‘2:45‘, ‘3:01‘, ‘2:01‘])>>> james = Athlete(‘james Jones‘)>>> type(james)<type ‘instance‘>>>> james<__main__.Athlete instance at 0x10691a5a8>

>>> james.name‘james Jones‘>>> james.dob>>> james.times[]>>> sarah.name‘sarah Sweeney‘>>> sarah.dob‘2002-02-22‘>>> sarah.times[‘2:45‘, ‘3:01‘, ‘2:01‘]

Custom Classes

#print_detail.pyfrom Athlete import Athletedef print_detail(file_name):    try:        with open(file_name+‘.txt‘) as data:            time_list = data.read().replace(‘-‘,‘:‘).replace(‘.‘,‘:‘)            time_list =  time_list.strip().split(‘,‘)            return Athlete(time_list.pop(0),time_list.pop(0),time_list)    except IOError as err:        print(‘file error:‘+str(err))        

#Athlete.pyclass Athlete:    def __init__(self,name,dob=None,times=[]):        self.name = name        self.dob = dob        self.times = times    def top3(self):        return sorted(set(self.times))[0:3]    def add_time(self,a_time):        self.times.append(a_time)    def add_times(self,time_list):        self.times.extend(time_list)

>>> import print_detail>>> james = print_detail.print_detail(‘james2‘)>>> type(james)<type ‘instance‘>>>> james.name‘James Lee‘>>> james.dob‘2002:3:14‘>>> james.top3()[‘2:01‘, ‘2:16‘, ‘2:22‘]>>> james.add_time(‘1.99‘)>>> james.top3()[‘1.99‘, ‘2:01‘, ‘2:16‘]>>> james.add_times([1.11,1.22])>>> james.top3()[1.11, 1.22, ‘1.99‘]    

If the above two files are no longer in the same directory, you need to use Sys.path.append () in print_detail.py to join the athlete.py path

Head_first_python Study Notes (iv)