[issue16669] Docstrings for namedtuple

[Peter Otten]

Peter Otten added the comment:

Here's a variant that builds on your code, but makes for a nicer API. Single-line docstrings can be passed along with the attribute name, and with namedtuple.with_docstrings(... all info required to build the class ...) from a user perspective the factory looks like a class method:

from functools import partial
from collections import namedtuple


def _with_docstrings(cls, typename, field_names_with_doc,
                     *, verbose=False, rename=False, doc=None):
    field_names = []
    field_docs = []
    if isinstance(field_names_with_doc, str):
        field_names_with_doc = [
            line for line in field_names_with_doc.splitlines() if line.strip()]
    for item in field_names_with_doc:
        if isinstance(item, str):
            item = item.split(None, 1)
        if len(item) == 1:
            [fieldname] = item
            fielddoc = None
        else:
            fieldname, fielddoc = item
        field_names.append(fieldname)
        field_docs.append(fielddoc)

    nt = cls(typename, field_names, verbose=verbose, rename=rename)

    for fieldname, fielddoc in zip(field_names, field_docs):
        if fielddoc is not None:
            new_property = property(getattr(nt, fieldname), doc=fielddoc)
            setattr(nt, fieldname, new_property)

    if doc is not None:
        nt.__doc__ = doc
    return nt

namedtuple.with_docstrings = partial(_with_docstrings, namedtuple)

if __name__ == "__main__":
    Point = namedtuple.with_docstrings("Point", "x abscissa\ny ordinate")
    Address = namedtuple.with_docstrings(
        "Address",
        """
        name Surname
        first_name First name

        city
        email Email address
        """)
    Whatever = namedtuple.with_docstrings(
        "Whatever",
        [("foo", "doc for\n foo"),
         ("bar", "doc for bar"),
         "baz"],
        doc="""The Whatever class.

Example for a namedtuple with multiline docstrings for its attributes.""")

----------
nosy: +peter.otten

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue16669>
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