Trying to query by str.casefold() but that generates a AttributeError: 'str' object has no attribute 'casefold'

[LaundroMat]

Here's a simple example, using Python 3.10.4 and pony 0.7.16

from pony.orm import *
db = Database()
class Person(db.Entity):
    name = Required(str)

db.bind(provider='sqlite', filename=':memory:')
db.generate_mapping(create_tables=True)

p1 = Person(name='John')
Person.exists(lambda p: str(p.name).lower() == 'john')   # True
Person.exists(lambda p: str(p.name).casefold() == 'john')   # AttributeError

That last line raises:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 2, in exists
  File "C:\***\lib\site-packages\pony\utils\utils.py", line 75, in cut_traceback
    reraise(exc_type, exc, last_pony_tb)
  File "C:\***\lib\site-packages\pony\utils\utils.py", line 88, in reraise
    try: raise exc.with_traceback(tb)
  File "C:\***\lib\site-packages\pony\orm\sqltranslation.py", line 1489, in getattr
    throw(AttributeError, '%r object has no attribute %r: {EXPR}' % (type2str(monad.type), attrname))
  File "C:\***\lib\site-packages\pony\utils\utils.py", line 101, in throw
    raise exc  # Set "pony.options.CUT_TRACEBACK = False" to see full traceback

AttributeError: 'str' object has no attribute 'casefold': str(p.name).casefold

I would like to use .casefold() because I want to make sure that e.g. the German word for street, Straβe, is considered equivalent to its alternative form Strasse (.casefold() turns Straβe intro strasse, while .lower() does not).

[Sajadrahimi]

Though this hasn't implemented yet, but the LOWER function does the same thing in MySQL if that helps. Also using .upper().lower() instead of .casefold() works in many cases.