Search code examples
python-3.xpython-imaging-library

Python 3, is PIL an alias for Pillow?

Python 3.5 on Windows 7 64-bit.

I'm confused -- IF one installs Pillow, THEN must one use the name of the superseded / uninstalled graphics library PIL as an alias for it?

Per the Pillow intallation instructions (http://pillow.readthedocs.io/en/3.3.x/installation.html), "Pillow and PIL cannot co-exist in the same environment. Before installing Pillow, please uninstall PIL." Okay:

D:\Python35>pip uninstall PIL

Cannot uninstall requirement PIL, not installed

Next:

D:\Python35>pip install Pillow

Requirement already satisfied (use --upgrade to upgrade): Pillow in d:\python35\lib\site-package

So now:

D:\Python35>python

Python 3.5.0 (v3.5.0:374f501f4567, Sep 13 2015, 02:27:37) [MSC v.1900 64 bit (AMD64)] on win32 Type "help", "copyright", "credits" or "license" for more information.

import Pillow

Traceback (most recent call last):

File "stdin", line 1, in module

ImportError: No module named 'Pillow'

Okay, so if there's no Pillow (or pillow), let's try:

import PIL

No error even though pip told me PIL wasn't installed. Next:

dir(PIL)

['PILLOW_VERSION', 'VERSION', 'builtins', 'cached', 'doc', 'file', 'loader'

Hmm, seemingly contradictory naming ala PIL versus Pillow?

PIL.PILLOW_VERSION

'3.4.1'

3.4.1 being as of this date the latest version of Pillow (https://pypi.python.org/pypi/Pillow)

I'm very confused -- the need to use PIL as an apparent alias for Pillow seems wrong. Yet per the above it seems to be necessary to do that?

Solution

  • The pillow library is the successor to the PIL library. It still uses the PIL package name to serve as a drop-in replacement.

    • install Pillow
    • import PIL

    The pip package name and python/import package name do not have to be the same. Since pillow is meant to replace PIL, it uses the same import name for compatibility.