Reconstruct Arabic sentences to be used in applications that do not support Arabic
Reconstruct Arabic sentences to be used in applications that don't support Arabic script.
Works with Python 3.x
Arabic script is very special with two essential features:
So when you try to print text written in Arabic script in an application – or a library – that doesn’t support Arabic you’re pretty likely to end up with something that looks like this:
We have two problems here, first, the characters are in the isolated form, which means that every character is rendered regardless of its surroundings, and second is that the text is written from left to right.
To solve the latter issue all we have to do is to use the Unicode bidirectional algorithm, which is implemented purely in Python in python-bidi. If you use it you’ll end up with something that looks like this:
The only issue left to solve is to reshape those characters and replace them with their correct shapes according to their surroundings. Using this library helps with the reshaping so we can get the proper result like this:
pip install --upgrade arabic-reshaper
If you're using Anaconda you can use
conda install -c mpcabd arabic-reshaper
import arabic_reshaper
text_to_be_reshaped = 'اللغة العربية رائعة'
reshaped_text = arabic_reshaper.reshape(text_to_be_reshaped)
PIL Image does not support reshaping out of the box, so to draw Arabic text on an Image
instance you would need to reshape
the text for sure.
For this example to work you need to run pip install --upgrade arabic-reshaper python-bidi pillow
import arabic_reshaper
text_to_be_reshaped = 'اللغة العربية رائعة'
reshaped_text = arabic_reshaper.reshape(text_to_be_reshaped)
# At this stage the text is reshaped, all letters are in their correct form
# based on their surroundings, but if you are going to print the text in a
# left-to-right context, which usually happens in libraries/apps that do not
# support Arabic and/or right-to-left text rendering, then you need to use
# get_display from python-bidi.
# Note that this is optional and depends on your usage of the reshaped text.
from bidi.algorithm import get_display
bidi_text = get_display(reshaped_text)
# At this stage the text in bidi_text can be easily rendered in any library
# that doesn't support Arabic and/or right-to-left, so use it as you'd use
# any other string. For example if you're using PIL.ImageDraw.text to draw
# text over an image you'd just use it like this...
from PIL import Image, ImageDraw, ImageFont
# We load Arial since it's a well known font that supports Arabic Unicode
font = ImageFont.truetype('Arial', 40)
image = Image.new('RGBA', (800, 600), (255,255,255,0))
image_draw = ImageDraw.Draw(image)
image_draw.text((10,10), bidi_text, fill=(255,255,255,128), font=font)
# Now the text is rendered properly on the image, you can save it to a file or just call `show` to see it working
image.show()
# For more details on PIL.Image and PIL.ImageDraw check the documentation
# See http://pillow.readthedocs.io/en/5.1.x/reference/ImageDraw.html?#PIL.ImageDraw.PIL.ImageDraw.Draw.text
You can configure the reshaper to your preferences, it has the following settings defined:
language
(Default: 'Arabic'
): Ignored, the reshaper works with Arabic,
Farsi, and Urdu, and most probably all other languages that use Arabic script.support_ligatures
(Default: True
): When this is set to False
, the
reshaper will not replace any ligatures, otherwise it will replace enabled
ligatures.delete_harakat
(Default: True
): When this is set to False
the reshaper
will not delete the harakat from the text, this will result in them showing up
in the reshaped text, you should enable this option if you are going to pass
the reshaped text to bidi.algorithm.get_display
because it will reverse the
text and you'd end up with harakat applied to the next letter instead of the
previous letter.delete_tatweel
(Default False
): When this is set to True
the reshaper
will delete the Tatweel character (U+0640) from the text before reshaping, this
can be useful when you want to support ligatures and don't care about Tatweel
getting deleted.shift_harakat_position
(Default False
): Whether to shift the Harakat
(Tashkeel) one position so they appear correctly when string is reversed, this
might solve the problem of Tashkeel in some systems, although for PIL.Image
for example, this is not needed.support_zwj
(Default True
): Whether to support ZWJ (U+200D
) or not.use_unshaped_instead_of_isolated
(Default False
): Use unshaped form
instead of isolated form, useful in some fonts that are missing the isolated
form of letters.Besides the settings above, you can enable/disable supported ligatures. For a full list of supported ligatures and their default status check the file default-config.ini.
There are multiple ways that you can configure the reshaper in, choose the one that suits your deployment:
configuration
Instead of directly using arabic_reshaper.reshape
function, define an
instance of arabic_reshaper.ArabicReshaper
, and pass your config dictionary
to its constructor's configuration
parameter like this:
from arabic_reshaper import ArabicReshaper
configuration = {
'delete_harakat': False,
'support_ligatures': True,
'RIAL SIGN': True, # Replace ر ي ا ل with ﷼
}
reshaper = ArabicReshaper(configuration=configuration)
text_to_be_reshaped = 'سعر المنتج ١٥٠ ر' + 'يال' # had to split the string for display
reshaped_text = reshaper.reshape(text_to_be_reshaped)
configuration_file
You can separte the configuration from your code, by copying the file
default-config.ini and change its settings,
then save it somewhere in your project, and then you can tell the reshaper
to use your new config file, just pass the path to your config file to its
constructor's configuration_file
parameter like this:
from arabic_reshaper import ArabicReshaper
reshaper = ArabicReshaper(configuration_file='/path/to/your/config.ini')
text_to_be_reshaped = 'سعر المنتج ١٥٠ ر' + 'يال' # had to split the string for display
reshaped_text = reshaper.reshape(text_to_be_reshaped)
Where in you config.ini
you can have something like this:
[ArabicReshaper]
delete_harakat = no
support_ligatures = yes
RIAL SIGN = yes
PYTHON_ARABIC_RESHAPER_CONFIGURATION_FILE
environment variableInstead of having to rewrite your old code to configure it like above, you can
define an environment variable with the name
PYTHON_ARABIC_RESHAPER_CONFIGURATION_FILE
and in its value put the full path
to the configuration file. This way the reshape function will pick it
automatically, and you won't have to change your old code.
If you intend to render the text in a TrueType® font, you can tell the library to generate its configuration by reading the font file to figure out what's supported in the font and what's not.
To use this feature you need to install the library with an extra option (not necessary when you install it with conda):
pip install --upgrade arabic-reshaper[with-fonttools]
Then you can use the reshaper like this:
import arabic_reshaper
reshaper = arabic_reshaper.ArabicReshaper(
arabic_reshaper.config_for_true_type_font(
'/path/to/true-type-font.ttf',
arabic_reshaper.ENABLE_ALL_LIGATURES
)
)
This will parse the font file, and figure out what ligatures it supports and enable them,
as well as whether it has isolated forms or use_unshaped_instead_of_isolated
should be
enabled.
The second parameter to config_for_true_type_font
can be one of
ENABLE_NO_LIGATURES
ENABLE_SENTENCES_LIGATURES
ENABLE_WORDS_LIGATURES
ENABLE_LETTERS_LIGATURES
ENABLE_ALL_LIGATURES
(default)which controls what ligatures to look for, depending on your usage, see default-config.ini to know what ligatures are there.
Harakat or Tashkeel
might not show up properly in their correct place, depending on the application
or the library that is doing the rendering for you, so you might want to enable
the shift_harakat_position
option if you face this problem.
This work is licensed under MIT License.
Online Arabic Reshaper: http://pydj.mpcabd.xyz/arabic-reshaper/
https://github.com/mpcabd/python-arabic-reshaper/tarball/master
future
. See #88.fonttools
under Python 2__version__.py
and default-config.ini
files, as they were causing problems for people who package their apps using pyinstaller or buildozer.use_unshaped_instead_of_isolated
to get around some fonts missing the isolated form for letters.BROKEN please make sure not to use this version.
shift_harakat_position
to try to get around the Tashkeel problemdelete_tatweel
Fix error message formatting
Fix error message formatting
Use Exception
instead of Error
.
Use pkg_resources.resource_filename
instead of depending on __file__
to access default-config.ini
.
Include default-config.ini in setup.py
Abdullah Diab (mpcabd) Email: mpcabd@gmail.com Blog: http://mpcabd.xyz
For more info visit my blog post here