以下腳本摘自笨學python，個人添加了備註

------------------------------------------------------------

1、腳本

from sys import argv
from os.path import exists
script,from_file,to_file = argv
print("Copy file %s to file %s" %(from_file,to_file))
#以讀的方式打開from_file
in_file = open(from_file,"r")
#將in_file文檔的內容讀取出來
indata = in_file.read()
#將in_file文檔的內容打印出來
print(indata)

print("the input file is %d bytes long" %len(indata))
print("Does the output file exists? %r" %exists(to_file))
print ("ready,hit RETURN to continue, CTRL-C to abort.")
#以讀的方式打開to_file
out_file = open (to_file,‘w‘)
#將indata的內容寫入out_file
out_file.write(indata)
#在寫入後，再次以讀的方式打開to_file
out_file = open(to_file,‘r‘)
#將out_file文檔的內容讀取出來
outdata = out_file.read()
#將out_file文檔的內容打印出來
print(outdata)

out_file.close()
in_file.close()
print("Alright,all done.")

2、執行結果

3、01txt內容為：

文件A的內容復制到B