From 0a40849eb99a0357113bff10434ec6605e3ae96b Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Mon, 8 Jun 2020 12:38:41 -0700 Subject: [PATCH] Minor improvement to the namedtuple implementation (GH-20741) * Cleaner way to build the arg list with a trailing comma when required * Fix appearance of __new__ in help() --- Lib/collections/__init__.py | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/Lib/collections/__init__.py b/Lib/collections/__init__.py index 1e3b54ccf9c..6a06cc6a64f 100644 --- a/Lib/collections/__init__.py +++ b/Lib/collections/__init__.py @@ -399,7 +399,9 @@ def namedtuple(typename, field_names, *, rename=False, defaults=None, module=Non # Variables used in the methods and docstrings field_names = tuple(map(_sys.intern, field_names)) num_fields = len(field_names) - arg_list = repr(field_names).replace("'", "")[1:-1] + arg_list = ', '.join(field_names) + if num_fields == 1: + arg_list += ',' repr_fmt = '(' + ', '.join(f'{name}=%r' for name in field_names) + ')' tuple_new = tuple.__new__ _dict, _tuple, _len, _map, _zip = dict, tuple, len, map, zip @@ -410,6 +412,7 @@ def namedtuple(typename, field_names, *, rename=False, defaults=None, module=Non namespace = {'_tuple_new': tuple_new, '__builtins__': None, '__name__': f'namedtuple_{typename}'} __new__ = eval(s, namespace) + __new__.__name__ = '__new__' __new__.__doc__ = f'Create new instance of {typename}({arg_list})' if defaults is not None: __new__.__defaults__ = defaults