diff options
Diffstat (limited to 'Lib/collections/__init__.py')
| -rw-r--r-- | Lib/collections/__init__.py | 66 |
1 files changed, 15 insertions, 51 deletions
diff --git a/Lib/collections/__init__.py b/Lib/collections/__init__.py index b1c82b4..355c0c1 100644 --- a/Lib/collections/__init__.py +++ b/Lib/collections/__init__.py @@ -315,10 +315,10 @@ def namedtuple(typename, field_names, verbose=False, rename=False): """ - # Parse and validate the field names. Validation serves two purposes, - # generating informative error messages and preventing template injection attacks. + # Validate the field names. At the user's option, either generate an error + # message or automatically replace the field name with a valid name. if isinstance(field_names, str): - field_names = field_names.replace(',', ' ').split() # names separated by whitespace and/or commas + field_names = field_names.replace(',', ' ').split() field_names = list(map(str, field_names)) if rename: seen = set() @@ -333,15 +333,19 @@ def namedtuple(typename, field_names, verbose=False, rename=False): seen.add(name) for name in [typename] + field_names: if not all(c.isalnum() or c=='_' for c in name): - raise ValueError('Type names and field names can only contain alphanumeric characters and underscores: %r' % name) + raise ValueError('Type names and field names can only contain ' + 'alphanumeric characters and underscores: %r' % name) if _iskeyword(name): - raise ValueError('Type names and field names cannot be a keyword: %r' % name) + raise ValueError('Type names and field names cannot be a ' + 'keyword: %r' % name) if name[0].isdigit(): - raise ValueError('Type names and field names cannot start with a number: %r' % name) + raise ValueError('Type names and field names cannot start with ' + 'a number: %r' % name) seen = set() for name in field_names: if name.startswith('_') and not rename: - raise ValueError('Field names cannot start with an underscore: %r' % name) + raise ValueError('Field names cannot start with an underscore: ' + '%r' % name) if name in seen: raise ValueError('Encountered duplicate field name: %r' % name) seen.add(name) @@ -352,13 +356,14 @@ def namedtuple(typename, field_names, verbose=False, rename=False): field_names = tuple(field_names), num_fields = len(field_names), arg_list = repr(tuple(field_names)).replace("'", "")[1:-1], - repr_fmt = ', '.join(_repr_template.format(name=name) for name in field_names), + repr_fmt = ', '.join(_repr_template.format(name=name) + for name in field_names), field_defs = '\n'.join(_field_template.format(index=index, name=name) for index, name in enumerate(field_names)) ) - # Execute the template string in a temporary namespace and - # support tracing utilities by setting a value for frame.f_globals['__name__'] + # Execute the template string in a temporary namespace and support + # tracing utilities by setting a value for frame.f_globals['__name__'] namespace = dict(__name__='namedtuple_%s' % typename) try: exec(class_definition, namespace) @@ -1122,44 +1127,3 @@ class UserString(Sequence): return self.__class__(self.data.translate(*args)) def upper(self): return self.__class__(self.data.upper()) def zfill(self, width): return self.__class__(self.data.zfill(width)) - - - -################################################################################ -### Simple tests -################################################################################ - -if __name__ == '__main__': - # verify that instances can be pickled - from pickle import loads, dumps - Point = namedtuple('Point', 'x, y', True) - p = Point(x=10, y=20) - assert p == loads(dumps(p)) - - # test and demonstrate ability to override methods - class Point(namedtuple('Point', 'x y')): - __slots__ = () - @property - def hypot(self): - return (self.x ** 2 + self.y ** 2) ** 0.5 - def __str__(self): - return 'Point: x=%6.3f y=%6.3f hypot=%6.3f' % (self.x, self.y, self.hypot) - - for p in Point(3, 4), Point(14, 5/7.): - print (p) - - class Point(namedtuple('Point', 'x y')): - 'Point class with optimized _make() and _replace() without error-checking' - __slots__ = () - _make = classmethod(tuple.__new__) - def _replace(self, _map=map, **kwds): - return self._make(_map(kwds.get, ('x', 'y'), self)) - - print(Point(11, 22)._replace(x=100)) - - Point3D = namedtuple('Point3D', Point._fields + ('z',)) - print(Point3D.__doc__) - - import doctest - TestResults = namedtuple('TestResults', 'failed attempted') - print(TestResults(*doctest.testmod())) |