另一种右拆分解决方案：

# to get extension only

s = 'test.ext'

if '.' in s: ext = s.rsplit('.', 1)[1]

# or, to get file name and extension

def split_filepath(s):
    """
    get filename and extension from filepath 
    filepath -> (filename, extension)
    """
    if not '.' in s: return (s, '')
    r = s.rsplit('.', 1)
    return (r[0], r[1])

为了好玩。。。只需收集dict中的扩展，并在文件夹中跟踪所有扩展。然后，只要拉动你想要的延伸部分。

import os

search = {}

for f in os.listdir(os.getcwd()):
    fn, fe = os.path.splitext(f)
    try:
        search[fe].append(f)
    except:
        search[fe]=[f,]

extensions = ('.png','.jpg')
for ex in extensions:
    found = search.get(ex,'')
    if found:
        print(found)

最简单的获取方法是使用mimtypes，下面是示例：

import mimetypes

mt = mimetypes.guess_type("file name")
file_extension =  mt[0]
print(file_extension)

# try this, it works for anything, any length of extension
# e.g www.google.com/downloads/file1.gz.rs -> .gz.rs

import os.path

class LinkChecker:

    @staticmethod
    def get_link_extension(link: str)->str:
        if link is None or link == "":
            return ""
        else:
            paths = os.path.splitext(link)
            ext = paths[1]
            new_link = paths[0]
            if ext != "":
                return LinkChecker.get_link_extension(new_link) + ext
            else:
                return ""

对于简单的用例，一个选项可能是从点拆分：

>>> filename = "example.jpeg"
>>> filename.split(".")[-1]
'jpeg'

文件没有扩展名时没有错误：

>>> "filename".split(".")[-1]
'filename'

但你必须小心：

>>> "png".split(".")[-1]
'png'    # But file doesn't have an extension

也不会在Unix系统中处理隐藏文件：

>>> ".bashrc".split(".")[-1]
'bashrc'    # But this is not an extension

对于一般用途，首选os.path.splitext

我知道我迟到了

这是我的简单解决方案

file = '/foo/bar/whatever.ext'
extension = file.split('.')[-1]
print(extension)

#output will be ext