python 获取文件拓展名

import os
a = 'var/label/txt/123.txt'
print(os.path.splitext(a))

b = 'var/label/txt/123'

print(os.path.splitext(b))

输出

('var/label/txt/123', '.txt')

('var/label/txt/123', '')

from:

https://www.jianshu.com/p/f46c487593c3

https://www.runoob.com/python3/python3-upper-lower.html