1:mod:`imghdr` --- Determine the type of an image 2================================================ 3 4.. module:: imghdr 5 :synopsis: Determine the type of image contained in a file or byte stream. 6 7**Source code:** :source:`Lib/imghdr.py` 8 9-------------- 10 11The :mod:`imghdr` module determines the type of image contained in a file or 12byte stream. 13 14The :mod:`imghdr` module defines the following function: 15 16 17.. function:: what(filename, h=None) 18 19 Tests the image data contained in the file named by *filename*, and returns a 20 string describing the image type. If optional *h* is provided, the *filename* 21 is ignored and *h* is assumed to contain the byte stream to test. 22 23 .. versionchanged:: 3.6 24 Accepts a :term:`path-like object`. 25 26The following image types are recognized, as listed below with the return value 27from :func:`what`: 28 29+------------+-----------------------------------+ 30| Value | Image format | 31+============+===================================+ 32| ``'rgb'`` | SGI ImgLib Files | 33+------------+-----------------------------------+ 34| ``'gif'`` | GIF 87a and 89a Files | 35+------------+-----------------------------------+ 36| ``'pbm'`` | Portable Bitmap Files | 37+------------+-----------------------------------+ 38| ``'pgm'`` | Portable Graymap Files | 39+------------+-----------------------------------+ 40| ``'ppm'`` | Portable Pixmap Files | 41+------------+-----------------------------------+ 42| ``'tiff'`` | TIFF Files | 43+------------+-----------------------------------+ 44| ``'rast'`` | Sun Raster Files | 45+------------+-----------------------------------+ 46| ``'xbm'`` | X Bitmap Files | 47+------------+-----------------------------------+ 48| ``'jpeg'`` | JPEG data in JFIF or Exif formats | 49+------------+-----------------------------------+ 50| ``'bmp'`` | BMP files | 51+------------+-----------------------------------+ 52| ``'png'`` | Portable Network Graphics | 53+------------+-----------------------------------+ 54| ``'webp'`` | WebP files | 55+------------+-----------------------------------+ 56| ``'exr'`` | OpenEXR Files | 57+------------+-----------------------------------+ 58 59.. versionadded:: 3.5 60 The *exr* and *webp* formats were added. 61 62 63You can extend the list of file types :mod:`imghdr` can recognize by appending 64to this variable: 65 66 67.. data:: tests 68 69 A list of functions performing the individual tests. Each function takes two 70 arguments: the byte-stream and an open file-like object. When :func:`what` is 71 called with a byte-stream, the file-like object will be ``None``. 72 73 The test function should return a string describing the image type if the test 74 succeeded, or ``None`` if it failed. 75 76Example:: 77 78 >>> import imghdr 79 >>> imghdr.what('bass.gif') 80 'gif' 81 82
