python获取文件夹下数量

import os

totalSize = 0
fileNum = 0
dirNum = 0

def visitDir(path):
    global totalSize
    global fileNum
    global dirNum
    for lists in os.listdir(path):
        sub_path = os.path.join(path, lists)
        print(sub_path)
        if os.path.isfile(sub_path):
            fileNum = fileNum+1                      # 统计文件数量
            totalSize = totalSize+os.path.getsize(sub_path)  # 文件总大小
        elif os.path.isdir(sub_path):
            dirNum = dirNum+1                       # 统计文件夹数量
            visitDir(sub_path)                           # 递归遍历子文件夹

def sizeConvert(size):                                   # 单位换算
    K, M, G = 1024, 1024**2, 1024**3
    if size >= G:
        return str(size/G)+'G Bytes'
    elif size >= M:
        return str(size/M)+'M Bytes'
    elif size >= K:
        return str(size/K)+'K Bytes'
    else:
        return str(size)+'Bytes'

def main(path):
    if not os.path.isdir(path):
        print('Error:"', path, '" is not a directory or does not exist.')
        return
    visitDir(path)

def output(path):
    print('The total size of '+path+' is:'+sizeConvert(totalSize))
    print('The total number of files in '+path+' is:',fileNum)
    print('The total number of directories in '+path+' is:',dirNum)

if __name__ == '__main__':
    path = r'E://Files'
    main(path)
    output(path)