I actually like that python doesn't do locale aware case conversions. You can use ICU* for that, though it shows more warts (like the i in republic and that you have to handle Chinese banknotes differently as well):

  % env - LC_ALL=en_US.UTF-8 PATH="$PATH" python3
  Python 3.8.12 (default, Nov 13 2021, 10:49:08) 
  [Clang 11.0.3 (clang-1103.0.32.62)] on darwin
  Type "help", "copyright", "credits" or "license" for more information.
  >>> from icu import UnicodeString, Locale
  >>> s = b'the Republic of T\xc3\xbcrkiye'
  >>> s = s.decode()
  >>> s
  'the Republic of Türkiye'
  >>> lc = Locale("TR")
  >>> s = UnicodeString(s)
  >>> s
  <UnicodeString: 'the Republic of Türkiye'>
  >>> s = s.toUpper(lc)
  >>> s
  <UnicodeString: 'THE REPUBLİC OF TÜRKİYE'>
  >>> s = str(s)
  >>> s
  'THE REPUBLİC OF TÜRKİYE'
  >>> s.encode()
  b'THE REPUBL\xc4\xb0C OF T\xc3\x9cRK\xc4\xb0YE'
  >>> s = UnicodeString(s)
  >>> lc = Locale("CN")
  >>> s = s.toLower(lc)
  >>> s
  <UnicodeString: 'the republi̇c of türki̇ye'>
  >>> s = '壹,貳,參,肆,伍,陸,柒,捌,玖,拾,佰,仟,萬'
  >>> s.encode()
  b'\xe5\xa3\xb9,\xe8\xb2\xb3,\xe5\x8f\x83,\xe8\x82\x86,\xe4\xbc\x8d,\xe9\x99\xb8,\xe6\x9f\x92,\xe6\x8d\x8c,\xe7\x8e\x96,\xe6\x8b\xbe,\xe4\xbd\xb0,\xe4\xbb\x9f,\xe8\x90\xac'
  >>> s = UnicodeString(s)
  >>> s
  <UnicodeString: '壹,貳,參,肆,伍,陸,柒,捌,玖,拾,佰,仟,萬'>
  >>> s = s.toLower(lc)
  >>> s
  <UnicodeString: '壹,貳,參,肆,伍,陸,柒,捌,玖,拾,佰,仟,萬'>

* https://pypi.org/project/PyICU/

edit: Oh neat there's a hansfin keyword that I had not known about.

https://unicode-org.github.io/icu/userguide/locale/#keywords

https://stackoverflow.com/questions/6224177/how-to-convert-e...