Greek case mapping in Python

Greek case mapping is asymmetric:

Python case mapping uses language/locale insensitive full case mapping. Greek requires langauge sensitive mappings defined in CLDR transformations. These build on the data in UnicodeData.txt and SpecialCasing.txt.

The PyICU module supports Greek case mapping:

import icu
locale = icu.Locale('el')
test = 'Νεράιδα'
print(test.upper())
# Output: ΝΕΡΆΙΔΑ
print(icu.UnicodeString(test).toUpper(locale))
# Output: ΝΕΡΑΪΔΑ
print(icu.CaseMap.toUpper(locale, test))
# Output: ΝΕΡΑΪΔΑ

test2 = 'ήσουν ή εγώ ή εσύ'
print(test2.upper())
# Output: ΉΣΟΥΝ Ή ΕΓΏ Ή ΕΣΎ
print(icu.UnicodeString(test2).toUpper(locale))
# Output: ΗΣΟΥΝ Ή ΕΓΩ Ή ΕΣΥ
print(icu.CaseMap.toUpper(locale, test2))
# Output: ΗΣΟΥΝ Ή ΕΓΩ Ή ΕΣΥ

andjc/greek_case_mapping_python.md