New submission from Santiago M. Mola : PyUnicode_FromKindAndData copies input data and transforms it to the most compact representation. This behavior is not documented. Proposed wording:

The input buffer is copied and transformed into the canonical representation, if necessary. For example, if the buffer is a UCS4 string (PyUnicode_4BYTE_KIND) and it consists only of codepoints in the UCS1 range, it will be transformed into UCS1 (PyUnicode_1BYTE_KIND).

---------- assignee: docs@python components: Documentation messages: 361426 nosy: docs@python, smola priority: normal severity: normal status: open title: PyUnicode_FromKindAndData kind transformation is not documented versions: Python 3.5, Python 3.6, Python 3.7, Python 3.8, Python 3.9 _______________________________________ Python tracker https://bugs.python.org/issue39560 _______________________________________