VARCHAR(None, CHAR)

I have a query generated by sqlalchemy like this:

SELECT fattura_master.tipo_documento AS fattura_master_tipo_documento, fattura_master.sezionale || '/' || CAST(fattura_master.anno AS VARCHAR(None CHAR)) || '/' || CAST(fattura_master.numero AS VARCHAR(None CHAR)) AS pk
FROM fattura_master;

which generate the following error:

DatabaseError: (DatabaseError) ORA-00910: specified length too long for its datatype

I can't understand the syntax: VARCHAR(None CHAR). I suppose the error is generated by it. Isn't it?

j

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