如果您将使用操作系统的标准shell，则可以比使用纯python方式更快地获得结果。

Windows示例:

import os
import subprocess

def get_num_files(path):
    cmd = 'DIR \"%s\" /A-D /B /S | FIND /C /V ""' % path
    return int(subprocess.check_output(cmd, shell=True))

这就是fnmatch非常方便的地方:

import fnmatch

print len(fnmatch.filter(os.listdir(dirpath), '*.txt'))

详情:http://docs.python.org/2/library/fnmatch.html

一个答案与pathlib和没有加载到内存的整个列表:

from pathlib import Path

path = Path('.')

print(sum(1 for _ in path.glob('*')))  # Files and folders, not recursive
print(sum(1 for _ in path.glob('**/*')))  # Files and folders, recursive

print(sum(1 for x in path.glob('*') if x.is_file()))  # Only files, not recursive
print(sum(1 for x in path.glob('**/*') if x.is_file()))  # Only files, recursive

def count_em(valid_path):
   x = 0
   for root, dirs, files in os.walk(valid_path):
       for f in files:
            x = x+1
print "There are", x, "files in this directory."
return x

摘自本文

卢克的代码重新格式化。

import os

print len(os.walk('/usr/lib').next()[2])

import os

_, _, files = next(os.walk("/usr/lib"))
file_count = len(files)