【样例输入】
src.txt里面存储内容为: This is a Book
【样例输出】
生成文件dest.txt。内容为: this is a book
【样例输入】
src.txt里面存储内容为: This is a Book
【样例输出】
生成文件dest.txt。内容为: this is a book
with open('src.txt', 'r') as o:
fdt = o.read()
o.close()
with open('dest.txt', 'w') as o:
o.write(fdt.lower())
o.close()