我是初学者并学习Python。
我已经创建了这个来练习函数编写。我知道没有必要这样写。
我的问题是out_file数据被删除，而不是替换为预期的in_file数据。
from sys import argv
script, in_file, out_file = argv
print "Copying from filename '%s' to filename '%s'" % (in_file, out_file)
print "The input data reads as: \n"
in_file = open(in_file)
print in_file.read()
print "The file to be overwritten originally reads as \n"
out_file = open(out_file, 'w+')
print out_file.read()
print "Now, to practice function writing, we will use one to overwrite:"
def overwrite():
out_file.write(in_file.read())
print out_file.read()
print "The overwritten file now reads as:\n"
overwrite()
因此＆gt; python ex20.py cat.txt dog.txt 的输出是:(其中dog.txt =“狗是最好的”，而cats.txt =“猫是最好的“）
Copying from filename 'cat' to filename 'dog'
The input data reads as:
cats are the best
The file to be overwritten originally reads as
Now, to practice function writing, we will use one to overwrite:
The overwritten file now reads as: