查找前10最大文件

当文件数量太多时，就

IndexError: list index out of range。。。。。

import os
from os.path import join,getsize

def formatsize(bytes):
    try:
        bytes = float(bytes)
        kb = bytes / 1024
    except Exception as e:
        print("wrong format string")
        return "error"

    if kb>1024:
        M=kb/1024
        if M>1024:
            G=M/1024
            return "%.2fG" %(G)
        else:
            return "%.2fM" %(M)
    else:
        return "%.2fkb" %(kb)

l={}
for root,dirs,files in os.walk(r"C:UsersjzhangDownloads"):
    for file in files:
        file1=join(root,file)
        # print(file1,getsize(file1))
        l[file]=getsize(file1)
print(len(l))
k=sorted(l.items(),key=lambda l:l[1],reverse=True)

for i in range(0,10):
    # print(k[i][0],k[i][1])
    print(k[i][0],formatsize(k[i][1]))