shutil －一种高层次的文件操作工具，强大之处是在对文件的复制与删除操作支持比较好。
在代码中用到copyfileobj(),主要是将url返回的数据复制到jpg文件中，形成一个图形
if result.status_code == 200:
#将图片数据copy
with open(filename,'wb') as f:
result.raw.decode_content = True
shutil.copyfileobj(result.raw,f)```
1. `copyfileobj(fsrc,fdst[,length]]`
copy the contents of the file-like object fsrc to the file-like object fdst. The integer length, if given, is the buffer size.
2. `copyfile(src,dat)`
从源src复制到dst中，前提是目标地址具有可写权限。
3. `copymode(src,dst)`
copy the permission bits from src to dst.只会复制权限，其他东西并不会复制
4. `copystat(src,dst)`
copy the permission bits,last access time, and last modification time from src to dst.
5. `copy(src,dst)`
copy the file src to the file or directory dst.
6. `copy2(src,dst)`
similar to copy(), but last access time and last modification time are copied as well. cp -p
6. `copytree(olddir,newdir,True/False)`
如果是Truename将保持文件夹下的符号链接
7. `rmtree(path)`
delete an entire directory tree, path must point to a directory
8. `move(src,dst)`
move a file or directory to another location.
