:mod:`imghdr2` --- Determine the type of an image

---

The :mod:`imghdr2` module determines the type of image contained in a file or byte stream. It was originally imghdr in the Python standard library, but is now deprecated. This module is a drop-in replacement for the original, with the same API.

Install with pip install imghdr2.

The :mod:`imghdr2` module defines the following function:

.. function:: what(file, h=None)

   Tests the image data contained in the file named by *file*, and returns a
   string describing the image type.  If optional *h* is provided, the *file*
   argument is ignored and *h* is assumed to contain the byte stream to test.

The following image types are recognized, as listed below with the return value from :func:`what`:

Value	Image format
'rgb'	SGI ImgLib Files
'gif'	GIF 87a and 89a Files
'pbm'	Portable Bitmap Files
'pgm'	Portable Graymap Files
'ppm'	Portable Pixmap Files
'tiff'	TIFF Files
'rast'	Sun Raster Files
'xbm'	X Bitmap Files
'jpeg'	JPEG data in JFIF or Exif formats
'bmp'	BMP files
'png'	Portable Network Graphics
'webp'	WebP files
'exr'	OpenEXR Files

You can extend the list of file types :mod:`imghdr2` can recognize by appending to tests. It is a list of functions performing the individual tests. Each function takes two arguments: the byte-stream and an open file-like object. When :func:`what` is called with a byte-stream, the file-like object will be None. The test function should return a string describing the image type if the test succeeded, or None if it failed.

Example:

>>> import imghdr2
>>> imghdr2.what('bass.gif')
'gif'