艰苦学习Python练习17额外问题(S)

Question

我正在做Zed Shaw的奇妙学习Python The Hard Way,但是另外一个问题让我感到难过:第9-10行可以写成一行,怎么样？我尝试了一些不同的想法,但无济于事.我可以继续前进,但那有什么乐趣呢？

from sys import argv
from os.path import exists

script, from_file, to_file = argv

print "Copying from %s to %s" % (from_file, to_file)

# we could do these two on one line too, how?
input = open(from_file)
indata = input.read()

print "The input file is %d bytes long" % len(indata)

print "Does the output file exist? %r" % exists(to_file)
print "Ready, hit RETURN to continue, CTRL-C to abort."
raw_input()

output = open(to_file, 'w')
output.write(indata)

print "Alright, all done."

Zed还写道,他可以在一行中完成整个剧本.我不确定他的意思是什么.

随意帮助我,无论你想要什么:通过给出答案或仅仅提示 - 并且可能包括对问题的折叠或隐藏答案.

Answer 1

indata = open(from_file).read()

Answer 2

shutil是在Python中执行单行文件副本的方法:

shutil.copy(sys.argv[1], sys.argv[2])

import shutil, sys然而,将它放在与此相同的行(当然,在它们之间用分号)将是风格上的傻瓜;-).

Answer 3

那么你可以做"代数替换",对吧？...假设你不关心"UI"......

open(to_file, 'w').write(open(from_file).read())