python查找文件夹下特定文件行数

import os
def countLines(fname):
    try:
        with open(fname) as f:
            data = f.readlines()
    except FileNotFoundError:
        print(fname + 'does not exist')
    lens = len (data)
    print(fname.split('\')[0]+' has ' + str(lens) + ' lines')
#path ='./testdata'
path ='./'
print(os.getcwd())
for fname in os.listdir(path):
    if fname.endswith('.txt'):
        file_path = os.path.join(path,fname)
        countLines (file_path)
#删除、创建文件目录
    if os.path.exist('./output'):
         shutil.rmtree("./output")
    os.mkdir("./output")