gh-91217: deprecate imghdr (#91461)

* Deprecate imghdr

Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>

* Update Doc/whatsnew/3.11.rst

Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>

* Inline `imghdr` into `email.mime.image`

Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>
Co-authored-by: Barry Warsaw <barry@python.org>
This commit is contained in:
Brett Cannon 2022-04-13 10:47:41 -07:00 committed by GitHub
parent dfbc792a4b
commit 3fc57e8f6f
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8 changed files with 128 additions and 23 deletions

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@ -1,9 +1,6 @@
# Import smtplib for the actual sending function
import smtplib
# And imghdr to find the types of our images
import imghdr
# Here are the email package modules we'll need
from email.message import EmailMessage
@ -22,7 +19,7 @@ for file in pngfiles:
with open(file, 'rb') as fp:
img_data = fp.read()
msg.add_attachment(img_data, maintype='image',
subtype=imghdr.what(None, img_data))
subtype='jpeg')
# Send the email via our own SMTP server.
with smtplib.SMTP('localhost') as s:

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@ -180,11 +180,12 @@ Here are the classes:
A subclass of :class:`~email.mime.nonmultipart.MIMENonMultipart`, the
:class:`MIMEImage` class is used to create MIME message objects of major type
:mimetype:`image`. *_imagedata* is a string containing the raw image data. If
this data can be decoded by the standard Python module :mod:`imghdr`, then the
subtype will be automatically included in the :mailheader:`Content-Type` header.
Otherwise you can explicitly specify the image subtype via the *_subtype*
argument. If the minor type could not be guessed and *_subtype* was not given,
then :exc:`TypeError` is raised.
this data type can be detected (jpeg, png, gif, tiff, rgb, pbm, pgm, ppm,
rast, xbm, bmp, webp, and exr attempted), then the subtype will be
automatically included in the :mailheader:`Content-Type` header. Otherwise
you can explicitly specify the image subtype via the *_subtype* argument.
If the minor type could not be guessed and *_subtype* was not given, then
:exc:`TypeError` is raised.
Optional *_encoder* is a callable (i.e. function) which will perform the actual
encoding of the image data for transport. This callable takes one argument,

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@ -856,6 +856,7 @@ Deprecated
* :mod:`cgitb`
* :mod:`chunk`
* :mod:`crypt`
* :mod:`imghdr`
(Contributed by Brett Cannon in :issue:`47061`.)

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@ -6,13 +6,113 @@
__all__ = ['MIMEImage']
import imghdr
from email import encoders
from email.mime.nonmultipart import MIMENonMultipart
# Originally from the imghdr module.
def _what(h):
for tf in tests:
if res := tf(h):
return res
else:
return None
tests = []
def _test_jpeg(h):
"""JPEG data with JFIF or Exif markers; and raw JPEG"""
if h[6:10] in (b'JFIF', b'Exif'):
return 'jpeg'
elif h[:4] == b'\xff\xd8\xff\xdb':
return 'jpeg'
tests.append(_test_jpeg)
def _test_png(h):
if h.startswith(b'\211PNG\r\n\032\n'):
return 'png'
tests.append(_test_png)
def _test_gif(h):
"""GIF ('87 and '89 variants)"""
if h[:6] in (b'GIF87a', b'GIF89a'):
return 'gif'
tests.append(_test_gif)
def _test_tiff(h):
"""TIFF (can be in Motorola or Intel byte order)"""
if h[:2] in (b'MM', b'II'):
return 'tiff'
tests.append(_test_tiff)
def _test_rgb(h):
"""SGI image library"""
if h.startswith(b'\001\332'):
return 'rgb'
tests.append(_test_rgb)
def _test_pbm(h):
"""PBM (portable bitmap)"""
if len(h) >= 3 and \
h[0] == ord(b'P') and h[1] in b'14' and h[2] in b' \t\n\r':
return 'pbm'
tests.append(_test_pbm)
def _test_pgm(h):
"""PGM (portable graymap)"""
if len(h) >= 3 and \
h[0] == ord(b'P') and h[1] in b'25' and h[2] in b' \t\n\r':
return 'pgm'
tests.append(_test_pgm)
def _test_ppm(h):
"""PPM (portable pixmap)"""
if len(h) >= 3 and \
h[0] == ord(b'P') and h[1] in b'36' and h[2] in b' \t\n\r':
return 'ppm'
tests.append(_test_ppm)
def _test_rast(h):
"""Sun raster file"""
if h.startswith(b'\x59\xA6\x6A\x95'):
return 'rast'
tests.append(_test_rast)
def _test_xbm(h):
"""X bitmap (X10 or X11)"""
if h.startswith(b'#define '):
return 'xbm'
tests.append(_test_xbm)
def _test_bmp(h):
if h.startswith(b'BM'):
return 'bmp'
tests.append(_test_bmp)
def _test_webp(h):
if h.startswith(b'RIFF') and h[8:12] == b'WEBP':
return 'webp'
tests.append(_test_webp)
def _test_exr(h):
if h.startswith(b'\x76\x2f\x31\x01'):
return 'exr'
tests.append(_test_exr)
class MIMEImage(MIMENonMultipart):
"""Class for generating image/* type MIME documents."""
@ -20,11 +120,11 @@ class MIMEImage(MIMENonMultipart):
_encoder=encoders.encode_base64, *, policy=None, **_params):
"""Create an image/* type MIME document.
_imagedata is a string containing the raw image data. If this data
can be decoded by the standard Python `imghdr' module, then the
subtype will be automatically included in the Content-Type header.
Otherwise, you can specify the specific image subtype via the _subtype
parameter.
_imagedata is a string containing the raw image data. If the data
type can be detected (jpeg, png, gif, tiff, rgb, pbm, pgm, ppm,
rast, xbm, bmp, webp, and exr attempted), then the subtype will be
automatically included in the Content-Type header. Otherwise, you can
specify the specific image subtype via the _subtype parameter.
_encoder is a function which will perform the actual encoding for
transport of the image data. It takes one argument, which is this
@ -38,9 +138,8 @@ class MIMEImage(MIMENonMultipart):
header.
"""
if _subtype is None:
_subtype = imghdr.what(None, _imagedata)
if _subtype is None:
raise TypeError('Could not guess image MIME subtype')
if (_subtype := _what(_imagedata)) is None:
raise TypeError('Could not guess image MIME subtype')
MIMENonMultipart.__init__(self, 'image', _subtype, policy=policy,
**_params)
self.set_payload(_imagedata)

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@ -1,9 +1,14 @@
"""Recognize image file formats based on their first few bytes."""
from os import PathLike
import warnings
__all__ = ["what"]
warnings._deprecated(__name__, remove=(3, 13))
#-------------------------#
# Recognize image headers #
#-------------------------#

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@ -7,6 +7,7 @@ import time
import base64
import unittest
import textwrap
import warnings
from io import StringIO, BytesIO
from itertools import chain
@ -1591,7 +1592,6 @@ class TestMIMEImage(unittest.TestCase):
header='foobar'), missing)
# Test the basic MIMEApplication class
class TestMIMEApplication(unittest.TestCase):
def test_headers(self):

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@ -1,12 +1,13 @@
import imghdr
import io
import os
import pathlib
import unittest
import warnings
from test.support import findfile
from test.support import findfile, warnings_helper
from test.support.os_helper import TESTFN, unlink
imghdr = warnings_helper.import_deprecated("imghdr")
TEST_FILES = (
('python.png', 'png'),

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@ -0,0 +1 @@
Deprecate the imghdr module.