参考：https://www.cnblogs.com/lovychen/p/5291673.html
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#统计 /home/dir/ 下的文件夹个数
import os
path ="home/dir"
count = 0
for fn in os.listdir(path): #fn 表示的是文件名
count = count+1
print count
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获取文件夹下的文件的个数：
import os
path = os.getcwd() #获取当前路径
count = 0
for root,dirs,files in os.walk(path): #遍历统计
for each in files:
count += 1 #统计文件夹下文件个数
print count #输出结果
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