On 9 April 2016 at 10:56, Larry Hastings <[email protected]> wrote: > > > I have a straightforward question about the str object, specifically the > PyUnicodeObject. I've tried reading the source to answer the question > myself but it's nearly impenetrable. So I was hoping someone here who > understands the current implementation could answer it for me. > > Although the str object is immutable from Python's perspective, the C object > itself is mutable. For example, for dynamically-created strings the hash > field may be lazy-computed and cached inside the object. I was wondering if > there were other fields like this. For example, are there similar > lazy-computed cached objects for the different encoded versions (utf8 utf16) > of the str? What would really help an exhaustive list of the fields of a > str object that may ever change after the object's initial creation.
https://www.python.org/dev/peps/pep-0393/#specification should have most of the relevant details. Aside from the hash and the interned-or-not flag in the state, most things should be locked once the string is ready, except that generating the utf-8 and wchar_t forms is deferred until they're needed if they're not the same as the canonical form. Cheers, Nick. -- Nick Coghlan | [email protected] | Brisbane, Australia _______________________________________________ Python-Dev mailing list [email protected] https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com