判断文件类型在开发中非常常见的需求，怎样才能准确的判断文件类型呢？首先大家想到的是文件的后缀，但是非常遗憾的是这种方法是非常不靠谱的，因为文件的后缀是可以随意更改的，而python中有个小插件可以实现，下面我们就来详细探讨下
filetype.py
Small and dependency free Python package to infer file type and
MIME type checking the magic numbers signature of
a file or buffer.
This is a Python port from filetype Go package. Works in
Python 3 .
一个小巧*开放Python开发包，主要用来获得文件类型。包要求Python 3.
功能特色
•简单友好的API
•支持宽范围文件类型
•提供文件扩展名和MIME类型判断
•文件的MIME类型扩展新增
•通过文件（图像、视频、音频…）简单分析
•可插拔：添加新的自定义类型的匹配
•快，即使处理大文件
•只需要前261个字节表示的最大文件头，这样你就可以通过一个单字节
•依赖*（只是Python代码，没有C的扩展，没有libmagic绑定）
•跨平台文件识别
安装
pip install filetype
API
详情请查看 annotated API reference .
实例
简单的文件类型识别
type!')
支持类型
图片
• jpg
–
image/jpeg
• png
–
image/png
• gif
–
image/gif
• webp
–
image/webp
• cr2
–
image/x-canon-cr2
• tif
–
image/tiff
• bmp
–
image/bmp
• jxr
–
image/vnd.ms-photo
• psd
–
image/vnd.adobe.photoshop
• ico
– image/x-icon
视频
• mp4
–
video/mp4
• m4v
–
video/x-m4v
• mkv
–
video/x-matroska
• webm
–
video/webm
• mov
–
video/quicktime
• avi
–
video/x-msvideo
• wmv
–
video/x-ms-wmv
• mpg
–
video/mpeg
• flv
– video/x-flv
音频
• mid
–
audio/midi
• mp3
–
• m4a
–
audio/m4a
• ogg
–
audio/ogg
• flac
–
audio/x-flac
• wav
–
audio/x-wav
• amr
– audio/amr
资料库
• epub
– application/epub
zip
• zip
–
application/zip
• tar
–
application/x-tar
• rar
–
application/x-rar-compressed
• gz
–
application/gzip
• bz2
–
application/x-bzip2
• 7z
–
application/x-7z-compressed
• xz
–
application/x-xz
• pdf
–
application/pdf
• exe
–
application/x-msdownload
• swf
–
application/x-shockwave-flash
• rtf
–
application/rtf
• eot
–
application/octet-stream
• ps
–
application/postscript
• sqlite
–
application/x-sqlite3
• nes
–
application/x-nintendo-nes-rom
• crx
–
application/x-google-chrome-extension
• cab
–
application/vnd.ms-cab-compressed
• deb
–
application/x-deb
• ar
–
application/x-unix-archive
• Z
–
application/x-compress
• lz
– application/x-lzip
字体
• woff
–
application/font-woff
• woff2
–
application/font-woff
• ttf
–
application/font-sfnt
• otf
– application/font-sfnt
基准测试
使用链接中的文件进行测试，你可以点击获得到它： real files .
Environment: OSX x64 i7 2.7 Ghz
------------------------------------------------------------------------------------------
benchmark: 7 tests
------------------------------------------------------------------------------------------
Name (time in
ns)
Min
Max
Mean
StdDev
Median
IQR
Outliers(*) Rounds
Iterations
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
test_infer_image_from_bytes
357.6279
(1.0)
29,166.5395
(1.0)
1,642.3360
(1.0)
380.9934
(1.0)
1,509.9843
(1.0)
158.9457
(1.0)
9095;13752
102301
6
test_infer_audio_from_bytes
953.6743
(2.67)
96,082.6874
(3.29)
16,534.5880
(10.07)
3,002.1143
(7.88)
15,974.0448
(10.58)
953.6743
(6.00)
4514;6051
41528
1
test_infer_video_from_bytes
13,828.2776
(38.67)
272,989.2731
(9.36)
16,151.3144
(9.83)
3,361.2320
(8.82)
15,020.3705
(9.95)
953.6743
(6.00)
2522;2887
22193
1
test_infer_image_from_disk
15,974.0448
(44.67)
108,957.2906
(3.74)
18,621.0844
(11.34)
3,895.4441
(10.22)
17,166.1377
(11.37)
1,192.0929
(7.50)
1528;1804
10206
1
test_infer_video_from_disk
23,841.8579
(66.67)
229,120.2545
(7.86)
28,691.3476
(17.47)
6,242.9901
(16.39)
25,987.6251
(17.21)
4,053.1158
(25.50)
1987;1247
15651
1
test_infer_zip_from_disk
26,941.2994
(75.33)
230,073.9288
(7.89)
32,123.3861
(19.56)
7,524.4988
(19.75)
29,087.0667
(19.26)
4,768.3716
(30.00)
1349;1292
16132
1
test_infer_tar_from_disk
33,855.4382
(94.67)
164,031.9824
(5.62)
36,884.4401
(22.46)
4,489.4443
(11.78)
36,001.2054
(23.84)
953.6743
(6.00)
1036;1828
14666
1
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------