操作系统。Path提供了许多操作路径/文件名的函数。(文档)

Os.path.splitext接受一个路径，并将文件扩展名从路径的末尾分离出来。

import os

filepaths = ["/folder/soundfile.mp3", "folder1/folder/soundfile.flac"]

for fp in filepaths:
    # Split the extension from the path and normalise it to lowercase.
    ext = os.path.splitext(fp)[-1].lower()

    # Now we can simply use == to check for equality, no need for wildcards.
    if ext == ".mp3":
        print fp, "is an mp3!"
    elif ext == ".flac":
        print fp, "is a flac file!"
    else:
        print fp, "is an unknown file format."

给:

/folder/soundfile.mp3 is an mp3!
folder1/folder/soundfile.flac is a flac file!

如果你的文件上传了

import os


file= request.FILES['your_file_name']          #Your input file_name for your_file_name
ext = os.path.splitext(file.name)[-1].lower()


if ext=='.mp3':
    #do something

elif ext=='.xls' or '.xlsx' or '.csv':
    #do something

else:
    #The uploaded file is not the required format

我很惊讶没有一个答案建议使用pathlib库。

当然，它的使用是视情况而定的，但当涉及到文件处理或统计pathlib是黄金。

下面是一个片段:

import pathlib


def get_parts(p: str or pathlib.Path) -> None:
    p_ = pathlib.Path(p).expanduser().resolve()
    print(p_)
    print(f"file name: {p_.name}")
    print(f"file extension: {p_.suffix}")
    print(f"file extensions: {p_.suffixes}\n")


if __name__ == '__main__':
    file_path = 'conf/conf.yml'
    arch_file_path = 'export/lib.tar.gz'

    get_parts(p=file_path)
    get_parts(p=arch_file_path)

输出:

/Users/hamster/temp/src/pro1/conf/conf.yml
file name: conf.yml
file extension: .yml
file extensions: ['.yml']

/Users/hamster/temp/src/pro1/conf/lib.tar.gz
file name: lib.tar.gz
file extension: .gz
file extensions: ['.tar', '.gz']

查看模块fnmatch。它会达到你想要的效果。

import fnmatch
import os

for file in os.listdir('.'):
    if fnmatch.fnmatch(file, '*.txt'):
        print file

或者:

from glob import glob
...
for files in glob('path/*.mp3'): 
  do something
for files in glob('path/*.flac'): 
  do something else

从Python3.4开始使用。

from pathlib import Path
Path('my_file.mp3').suffix == '.mp3'

如果您正在处理包含句点的文件夹，则可以使用

Path('your_folder.mp3').is_file() and Path('your_folder.mp3').suffix == '.mp3'

确保后缀为.mp3的文件夹不会被解释为mp3文件。