Python文件操作之简化代码

一朝误入此门中，从此红尘了如空、、、、

程序这条路，当真是路漫漫、、、

这两天找到一本书，名为《笨方法学Python第三版》，全实例，感觉挺好的。需要的点书名下载，密码：gmpn

今天想说的是习题17，先看书中源码：

 1 from sys import argv
 2 from os.path import exists
 3 script, from_file, to_file = argv
 4 print "Copying from %s to %s" % (from_file, to_file)
 5 # we could do these two on one line too, how?
 6 in_file = open(from_file)
 7 indata = in_file.read()
 8 print "The input file is %d bytes long" % len(indata)
 9 print "Does the output file exist? %r" % exists(to_file)
10 print "Ready, hit RETURN to continue, CTRL-C to abort."
11 raw_input()
12 out_file = open(to_file, 'w')
13 out_file.write(indata)
14 print "Alright, all done."
15 out_file.close()
16 in_file.close()

我的代码稍微改了一下，因为作者是要在命令行下运行，而我用的是Eclipse，如下：

 1 #!/usr/bin/ python
 2 #-*- coding: utf-8 -*-
 3 # file:ex17.py
 4 
 5 from os.path import exists
 6 
 7 from_file = 'D:PythonProjectworkspaceExerciseExex16_simple.txt'
 8 to_file = 'D:PythonProjectworkspaceExerciseExex17_simple.txt'
 9 
10 print "Copying from %s to %s" % (from_file,to_file)
11 
12 #We could do these two on one line too,how?
13 in_file = open(from_file)
14 indata = in_file.read()
15 
16 print "The input file is %d bytes long" % len(indata)
17 
18 print "Does the output file exist? %r" % exists(to_file)
19 print "Ready,hit RETURN to continue, CTRL- C to abort."
20 raw_input()
21 
22 out_file = open(to_file,"w")
23 out_file.write(indata)
24 
25 print "Alright, all done."
26 
27 out_file.close()
28 in_file.close()

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看到后面的加分习题，作者说他能一行给写出来。。。就想了想，还真能做到。。。

file('D:PythonProjectworkspaceExerciseExex17_simple.txt','wb').write(file('D:PythonProjectworkspaceExerciseExex16_simple.txt','rb').read())

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运行成功，只不过是没有任何提示，不大友好，但不得不说Python真是易用，千万别想得太难、、、、