Rae Knowler - Python, Locales and Writing Systems

Python, Locales and Writing Systems Rae Knowler PyCon US May
2018

Who I am @RaeKnowler Python (Django, CKAN) PHP, Go, JavaScript
they/them/their https://www.flickr.com/photos/zurichtourism/5160475075

@RaeKnowler #PyCon2018

@RaeKnowler #PyCon2018 Python 3 is great Unicode by default! Source
file encoding assumed to be UTF-8 No need to specify u'foobar' for non-ascii strings

@RaeKnowler #PyCon2018 Python 3 is great Less of this:

@RaeKnowler #PyCon2018 Turkish i and ı http://gizmodo.com/382026/a-cellphones-missing-do t-kills-two-people-puts-three-more-in-jail Emine Çalçoban
Ramazan Çalçoban

@RaeKnowler #PyCon2018 Turkish i and ı Dotless: 'ı' (U+0131), 'I'
(U+0049) Dotted: 'i' (U+0069), 'İ' (U+0130) More details here: http://www.i18nguy.com/unicode/turkish-i18n.html

@RaeKnowler #PyCon2018 Turkish i and ı

@RaeKnowler #PyCon2018 Turkish i and ı - Solutions • PyICU:
a Python extension wrapping IBM’s International Components for Unicode C++ library (ICU). https://pypi.python.org/pypi/PyICU • Or… make a translation table and use str.translate() to replace characters when changing the case

@RaeKnowler #PyCon2018 Right-to-left writing systems https://en.wikipedia.org/wiki/File:Simtat_Aluf_Batslut.JPG

@RaeKnowler #PyCon2018 Right-to-left writing systems Unicode wants characters ordered logically,
not visually → we need bidirectional (bidi) support → pip install python-bidi

@RaeKnowler #PyCon2018 Right-to-left writing systems

@RaeKnowler #PyCon2018 Right-to-left writing systems Arabic letters have contextual forms.
Their placement in the text changes their shape. https://en.wikipedia.org/wiki/Arabic_script_in_Unicode#Contextual_forms

@RaeKnowler #PyCon2018 → Python Arabic Reshaper to the rescue: https://github.com/mpcabd/python-arabic-reshaper
Right-to-left writing systems

@RaeKnowler #PyCon2018 Right-to-left writing systems

@RaeKnowler #PyCon2018 Fullwidth and halfwidth characters Notice any difference? ---
Ｔｈｅ　ｑｕｉｃｋ　ｂｒｏｗｎ　ｆｏｘ　ｊｕｍｐｅｄ　ｏｖｅｒ　ｔｈｅ　ｌａｚｙ　ｄｏｇ． The quick brown fox jumped over the lazy dog.

@RaeKnowler #PyCon2018 Fullwidth and halfwidth characters Some fonts don't even
bother styling the fullwidth characters. --- Ｔｈｅ　ｑｕｉｃｋ　ｂｒｏｗｎ　ｆｏｘ　ｊｕｍｐｅｄ　ｏｖｅｒ　ｔｈｅ　ｌａｚｙ　ｄｏｇ． The quick brown fox jumped over the lazy dog.

@RaeKnowler #PyCon2018 Fullwidth and halfwidth characters 假借字, 形声字 Han characters
(in Chinese, Japanese, Korean) are fullwidth

@RaeKnowler #PyCon2018 Fullwidth and halfwidth characters 假借字, 形声字ミムメモヤユヨラリルレロワンﾐﾑﾒﾓﾔﾕﾖﾗﾘﾙﾚﾛﾜﾝ
There are fullwidth and halfwidth kana (Japanese)

@RaeKnowler #PyCon2018 Fullwidth and halfwidth characters 假借字, 形声字ミムメモヤユヨラリルレロワンﾐﾑﾒﾓﾔﾕﾖﾗﾘﾙﾚﾛﾜﾝ
なにぬねのは Hiragana (Japanese) are always fullwidth

@RaeKnowler #PyCon2018 Fullwidth and halfwidth characters Copyright © 2008 W3C®
(MIT, ERCIM, Keio), All Rights Reserved. https://www.w3.org/2007/02/japanese-layout/docs/aligned/japanese-layout-requirements-en.html

@RaeKnowler #PyCon2018 Fullwidth and halfwidth characters pip install jaconv

@RaeKnowler #PyCon2018 Fullwidth and halfwidth characters

@RaeKnowler #PyCon2018 Korean text https://en.wikipedia.org/wiki/Hangul#/media/File:Hangeul.svg

@RaeKnowler #PyCon2018 Korean text Lots more detail here: http://www.gernot-katzers-spice-pages.com /var/korean_hangul_unicode.html

@RaeKnowler #PyCon2018 Korean text Unicode canonical equivalence: You can build
the same character in several different ways, and they mean the same thing. 한 means the same as ㅎㅏㄴ

@RaeKnowler #PyCon2018 Korean text Unicode canonical equivalence: You can build
the same character in several different ways, and they mean the same thing. 한 means the same as ㅎㅏㄴ Normal Form D (NFD): ㅎㅏㄴ Normal Form C (NFC): 한

@RaeKnowler #PyCon2018 Korean text Unicode compatibility equivalence: There are multiple
code points for identical characters, for backwards compatibility reasons U+2160 (ROMAN NUMERAL ONE) is really the same thing as U+0049 (LATIN CAPITAL LETTER I) (https://docs.python.org/2/library/unicodedata.html)

@RaeKnowler #PyCon2018 Korean text

@RaeKnowler #PyCon2018 Security This is a huge topic! A couple
of quick examples...

@RaeKnowler #PyCon2018 Security - SQL Injection User input: I don't
like raisins Sanitised user input: 'I don\'t like raisins' Hex encoding of \ is 0x5C

@RaeKnowler #PyCon2018 Security - SQL Injection Hex encoding for 稞:
0xb8 0x5c User input: 0xb8' OR 1=1 Sanitised user input: '稞 OR 1=1'

@RaeKnowler #PyCon2018 Security - SQL Injection More details here: http://howto.hackallthethings.com
/2016/06/using-multi-byte-characters-to-nullify.html

@RaeKnowler #PyCon2018 Security - Address Bar Spoofing A nice google.com
link: http://google.com/test/test/test/تارﺎﻣا.ﻲﺑﺮﻋ This actually led to: http://تارﺎﻣا.ﻲﺑﺮﻋ/google.com/test/test/test

@RaeKnowler #PyCon2018 Security - Address Bar Spoofing More details here:
http://www.rafayhackingarticles.net/2016/08/google-c hrome-firefox-address-bar.html

@RaeKnowler #PyCon2018 Security - Unicode characters in urls https://аррӏе.com vs
https://apple.com

@RaeKnowler #PyCon2018 Security - Unicode characters in urls https://www.xn--80ak6aa92e.com/ vs
https://apple.com

@RaeKnowler #PyCon2018 Security - Unicode characters in urls Xudong Zheng,
Phishing with Unicode Domains: https://www.xudongz.com/blog/2017/idn-phishing/ Safari, Edge and Chrome: show an alert Firefox: see Zheng's page for a fix

@RaeKnowler #PyCon2018 Security - Unicode characters in urls Unicode trick
lets hackers hide phishing URLs (The Guardian, April 2017) https://www.theguardian.com/technology /2017/apr/19/phishing-url-trick-hackers

@RaeKnowler #PyCon2018 Security - Unicode characters in urls Spoofing URLs
with Unicode (Slashdot, May 2002) https://it.slashdot.org /story/02/05/28/0142248/spoofing-urls-with-unicode

@RaeKnowler #PyCon2018 Conclusions This stuff isn't easy … but it
is interesting! There are a lot of useful libraries out there. You won't be the first person to have your particular problem. Python 3 makes dealing with Unicode a lot easier.

@RaeKnowler #PyCon2018 Further links • The Absolute Minimum Every Software
Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!): http://www.joelonsoftware.com/articles/Unicode.html • Unicode, or why py3k was necessary: http://lukas-prokop.at/talks/pydays18-unicode/#1 • Dark corners of Unicode: https://eev.ee/blog/2015/09/12/dark-corners-of-unicode

@RaeKnowler #PyCon2018 Further links • I Can Text You A
Pile of Poo, But I Can’t Write My Name: https://modelviewculture.com/pieces/i-can-text-you-a-pile-of- poo-but-i-cant-write-my-name • Nope, Not Arabic: http://nopenotarabic.tumblr.com/ • Symbol Codes, Computing with Accents, Symbols and Foreign Scripts: http://sites.psu.edu/symbolcodes/

@RaeKnowler #PyCon2018 Thanks! @RaeKnowler [email protected]

Rae Knowler - Python, Locales and Writing Systems

Rae Knowler - Python, Locales and Writing Systems

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