HeadFirstPython---------（四）第六章（定制数据对象__打包代码与数据）

1、





实现下面的效果：



代码如下：

import os
os.chdir("D:/pythontest/HeadFirstPython/chapter6");
def sanitize(time_string):
if '-' in time_string:
splitter='-';

elif ':' in time_string:
splitter=':';
else:
return(time_string);
(mins,secs)=time_string.split(splitter);

return (mins+'.'+secs);
def get_coach_data(filename):
try:
with open(filename) as f:
data=f.readline();
return(data.strip().split(','));
except IOError as ioerr:
print('File error:'+str(ioerr));
return(None);
try:
james=get_coach_data('james2.txt');
julie=get_coach_data('julie2.txt');
mikey=get_coach_data('mikey2.txt');
sarah=get_coach_data('sarah2.txt');

(james_name,james_dob)=james.pop(0),james.pop(0);#
(julie_name,julie_dob)=julie.pop(0),julie.pop(0);
(mikey_name,mikey_dob)=mikey.pop(0),mikey.pop(0);
(sarah_name,sarah_dob)=sarah.pop(0),sarah.pop(0);
print(james_name+"'s fastest times are:"+str(sorted(set([sanitize(time_string) for time_string in james]))[0:3]));
print(julie_name+"'s fastest times are:"+str(sorted(set([sanitize(time_string) for time_string in julie]))[0:3]));
print(mikey_name+"'s fastest times are:"+str(sorted(set([sanitize(time_string) for time_string in mikey]))[0:3]));
print(sarah_name+"'s fastest times are:"+str(sorted(set([sanitize(time_string) for time_string in sarah]))[0:3]));
except IOError as err:
print("File error"+str(err));

2、改善，使用字典关联数据：

字典这是一个内置的数据结构（内置于Python中），允许将数据与键而不是数字关联。这样可以使内存中的数据与实际数据的结构保持一致。

代码如下：

sanitize1.py中的代码如下：

def sanitize(time_string):
if '-' in time_string:
splitter='-';

elif ':' in time_string:
splitter=':';
else:
return(time_string);
(mins,secs)=time_string.split(splitter);

return (mins+'.'+secs);

get_coach_data1.py中的代码如下

def get_coach_data(filename):
try:
with open(filename) as f:
data=f.readline();
return(data.strip().split(','));
except IOError as ioerr:
print('File error:'+str(ioerr));
return(None);

read.py主程序代码如下：

import os

import sanitize1

import get_coach_data1
os.chdir("D:/pythontest/HeadFirstPython/chapter6");
try:
james=get_coach_data1.get_coach_data('james2.txt');
julie=get_coach_data1.get_coach_data('julie2.txt');
mikey=gget_coach_data1.et_coach_data('mikey2.txt');
sarah=get_coach_data1.get_coach_data('sarah2.txt');

#利用字典的表达形式
james_data={};
james_data['Name']=james.pop(0);
james_data['DOB']=james.pop(0);
james_data['Times']=james;
print(james_data['Name']+"'s fastest times are: "+str(sorted(set([sanitize1.sanitize(t)for t in james_data['Times']]))[0:3]));

julie_data={};
julie_data['Name']=julie.pop(0);
julie_data['DOB']=julie.pop(0);
julie_data['Times']=julie;
print(julie_data['Name']+"'s fastest times are: "+str(sorted(set([sanitize1.sanitize(t)for t in julie_data['Times']]))[0:3]));

mikey_data={};
mikey_data['Name']=mikey.pop(0);
mikey_data['DOB']=mikey.pop(0);
mikey_data['Times']=mikey;
print(mikey_data['Name']+"'s fastest times are: "+str(sorted(set([sanitize1.sanitize(t)for t in mikey_data['Times']]))[0:3]));

sarah_data={};
sarah_data['Name']=sarah.pop(0);
sarah_data['DOB']=sarah.pop(0);
sarah_data['Times']=sarah;
print(sarah_data['Name']+"'s fastest times are: "+str(sorted(set([sanitize1.sanitize(t)for t in sarah_data['Times']]))[0:3]));

实验结果为：



3、对2中代码的进一步 的改善。（针对的是重复性代码）

sanitize1.py中的代码为：

import os
os.chdir("D:/pythontest/HeadFirstPython/chapter5");
def sanitize(time_string):
if '-' in time_string:
splitter='-';

elif ':' in time_string:
splitter=':';
else:
return(time_string);
(mins,secs)=time_string.split(splitter);

return (mins+'.'+secs);

get_coach_data1.py中的代码是：

import sanitize1
def get_coach_data(filename):
try:
with open(filename) as f:
data=f.readline();
templ=data.strip().split(',')
name_data={};
name_data['Name']=templ.pop(0);
name_data['DOB']=templ.pop(0);
name_data['Times']=str(sorted(set([sanitize1.sanitize(t) for t in templ]))[0:3]);
return name_data;

except IOError as ioerr:
print('File error:'+str(ioerr));
return(None);

chapter6.py主程序的代码为：

import os
import get_coach_data1
os.chdir("D:/pythontest/HeadFirstPython/chapter6");

try:
james=get_coach_data1.get_coach_data('james2.txt');
julie=get_coach_data1.get_coach_data('julie2.txt');
mikey=get_coach_data1.get_coach_data('mikey2.txt');
sarah=get_coach_data1.get_coach_data('sarah2.txt');

print(james['Name']+"'s fastest times are:"+james['Times']);
print(julie['Name']+"'s fastest times are:"+julie['Times']);
print(mikey['Name']+"'s fastest times are:"+mikey['Times']);
print(sarah['Name']+"'s fastest times are:"+sarah['Times']);
except IOError as err:
print("File error"+str(err));

运行结果为：



4、类的应用：

代码如下：

import os

import sanitize1
os.chdir("D:/pythontest/HeadFirstPython/chapter6");
class Athlete:
def __init__(self,a_name,a_dob=None,a_times=[]):
self.name=a_name;
self.dob=a_dob;
self.times=a_times;
def top3(self):
return (sorted(set([sanitize1.sanitize(t) for t in self.times]))[0:3]);
def get_coach_data(filename):
try:
with open(filename) as f:
data=f.readline();
templ=data.strip().split(',')

return (Athlete(templ.pop(0),templ.pop(0),templ));

except IOError as ioerr:
print('File error:'+str(ioerr));
return(None);
try:
james=get_coach_data('james2.txt');
julie=get_coach_data('julie2.txt');
mikey=get_coach_data('mikey2.txt');
sarah=get_coach_data('sarah2.txt');

print(james.name+"'s fastest times are:"+str(james.top3()));
print(julie.name+"'s fastest times are:"+str(julie.top3()));
print(mikey.name+"'s fastest times are:"+str(mikey.top3()));
print(sarah.name+"'s fastest times are:"+str(sarah.top3()));
except IOError as err:
print("File error"+str(err));运行结果为：



5、继承内置类的子类：

代码如下：

import os

os.chdir("D:/pythontest/HeadFirstPython/chapter6");

def sanitize(time_string):
if '-' in time_string:
splitter='-';
elif ':' in time_string:
splitter=':';
else:
return(time_string);
(mins,secs)=time_string.split(splitter);
return (mins+'.'+secs);

class AthleteList(list):
def __init__(self,a_name,a_dob=None,a_times=[]):
list.__init__([]);
self.name=a_name;
self.dob=a_dob;
self.extend(a_times);
def top3(self):
return (sorted(set([sanitize(t) for t in self]))[0:3]);
def get_coach_data(filename):
try:
with open(filename) as f:
data=f.readline();
templ=data.strip().split(','
da2d
);
return (AthleteList(templ.pop(0),templ.pop(0),templ));
except IOError as ioerr:
print('File error:'+str(ioerr));
return(None);
try:
james=get_coach_data('james2.txt');
julie=get_coach_data('julie2.txt');
mikey=get_coach_data('mikey2.txt');
sarah=get_coach_data('sarah2.txt');

print(james.name+"'s fastest times are:"+str(james.top3()));
print(julie.name+"'s fastest times are:"+str(julie.top3()));
print(mikey.name+"'s fastest times are:"+str(mikey.top3()));
print(sarah.name+"'s fastest times are:"+str(sarah.top3()));
except IOError as err:
print("File error"+str(err));

运行结果为：