import os
os.chdir('C:\Python33\HeadFirstPython\hfpy_code\chapter5')   #將工作空間修改為文件所在的目錄
#定義函數(shù)get_filedata從文件中取值
def get_filedata(filename):
    try:
        with open(filename)  as f:            #with語(yǔ)句打開(kāi)和自動(dòng)關(guān)閉文件
            data=f.readline()                 #從文件中逐行讀取字符
            return (data.strip().split(','))  #將字符間的空格清除后，用逗號(hào)分隔字符
    except IOError as ioerr:
        print ('File Error' + str(ioerr))     #異常處理，打印錯(cuò)誤
        return (None)
#定義函數(shù)modify_time_format將所有文件中的時(shí)分表達(dá)方式統(tǒng)一為“分.秒”
def modify_time_format(time_string):
    if "-" in time_string:
        splitter="-"
    elif ":" in time_string:
        splitter=":"
    else:
        splitter="."
    (mins, secs)=time_string.split(splitter)  #用分隔符splitter分隔字符后分別存入mins和secs
    return (mins+ '.' +secs)
#定義函數(shù)get_prev_three返回文件中排名前三的不重復(fù)的時(shí)間成績(jī)
def get_prev_three(filename):
    new_list=[modify_time_format(each_t) for each_t in get_filedata(filename)]   #采用列表推導(dǎo)將統(tǒng)一時(shí)分表達(dá)方式后的記錄生成新的列表
    delete_repetition=set(new_list)                                              #采用集合set函數(shù)刪除新列表中重復(fù)項(xiàng)，并生成新的集合
    in_order=sorted(delete_repetition)                                           #采用復(fù)制排序sorted函數(shù)對(duì)無(wú)重復(fù)性的新集合進(jìn)行排序
    return (in_order[0:3])                                                       #返回列表前三項(xiàng)
# 分別輸出對(duì)應(yīng)文件中排名前三的不重復(fù)的時(shí)間成績(jī)
print (get_prev_three("james.txt"))
print (get_prev_three("julie.txt"))
print (get_prev_three("mikey.txt"))
print (get_prev_three("sarah.txt"))

['2.01', '2.22', '2.34']
['2.11', '2.23', '2.59']
['2.22', '2.38', '2.49']
['2.18', '2.25', '2.39']