> In 3.1 it was the default encoding of string (the type str I guess).
No, what was used was what sys.getdefaultencoding(), which was already UTF-8 in 3.1 (I checked the source code).
At that time, the format used for representing `str` objects in memory depended on if you used a "narrow" (UTF-16) or "wide" (UTF-32) build of Python.
Fortunately, wide and narrow builds were abandonned in Python 3.2, with a new way of representing strings : current Python will use ASCII if there's no non-ASCII char, UCS-2 –UTF-16 without surrogate pairs — if there is no codepoint higher than U+FFFF, and UTF-32 else. But that did not exist in 3.1, where you could either use the "narrow" build of python (that used UTF-16) or the "wide" build (that used UTF-32).
No, what was used was what sys.getdefaultencoding(), which was already UTF-8 in 3.1 (I checked the source code).
At that time, the format used for representing `str` objects in memory depended on if you used a "narrow" (UTF-16) or "wide" (UTF-32) build of Python.
Fortunately, wide and narrow builds were abandonned in Python 3.2, with a new way of representing strings : current Python will use ASCII if there's no non-ASCII char, UCS-2 –UTF-16 without surrogate pairs — if there is no codepoint higher than U+FFFF, and UTF-32 else. But that did not exist in 3.1, where you could either use the "narrow" build of python (that used UTF-16) or the "wide" build (that used UTF-32).
See this article for a good overview of the history of strings in Python : https://tenthousandmeters.com/blog/python-behind-the-scenes-...