On 2/27/2018 9:32 AM, Serhiy Storchaka wrote:
27.02.18 15:37, INADA Naoki пише:
Of course, this change was backward incompatible.
Tools reading/writing docstring via AST will be broken by this change.
For example, it broke PyFlakes, and PyFlakes solved it already.
https://github.com/PyCQA/pyflakes/pull/273
Other examples:
coveragepy: https://bitbucket.org/ned/coveragepy/commits/99176232199b
pytest: https://github.com/pytest-dev/pytest/pull/2870
Last week, Mark Shannon reported issue about this backward
incompatibility.
As he said, this change losted lineno and column of docstring from AST.
While losing lineno and column is a loss, it is not so large. There are
existing issues with docstring position.
1. CPython and PyPy set different position for multiline strings. PyPy
sets the position of the start of string, but CPython sets the position
of the end of the string. A program that utilizes the docstring position
needs to handle both of these cases.
2. Usually the position of the docstring is used for determining the
absolute position of some fragments in the docstring (for example
doctests). But since the literal string can contain \n and escaped
newlines, and this information is lost in AST, the position of the
fragment can be determined accurately.
You obviously meant 'cannot be determined accurately', because for
reasons including the ones you gave, the relation between string
literals in code and the resulting string objects is many-to-one, (as
with int literals).
This is just a best effort approximation.
3. You can determine an approximate position of the docstring by
positions of preceding or following nodes.
--
Terry Jan Reedy
_______________________________________________
Python-Dev mailing list
Python-Dev@python.org
https://mail.python.org/mailman/listinfo/python-dev
Unsubscribe:
https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
