Lib/test/test_collections.py

import unittest
from test import test_support
from collections import namedtuple

class TestNamedTuple(unittest.TestCase):

    def test_factory(self):
        Point = namedtuple('Point', 'x y')
        self.assertEqual(Point.__name__, 'Point')
        self.assertEqual(Point.__doc__, 'Point(x, y)')
        self.assertEqual(Point.__slots__, ())
        self.assertEqual(Point.__module__, __name__)
        self.assertEqual(Point.__getitem__, tuple.__getitem__)

        self.assertRaises(ValueError, namedtuple, 'abc%', 'efg ghi')       # type has non-alpha char
        self.assertRaises(ValueError, namedtuple, 'class', 'efg ghi')      # type has keyword
        self.assertRaises(ValueError, namedtuple, '9abc', 'efg ghi')       # type starts with digit

        self.assertRaises(ValueError, namedtuple, 'abc', 'efg g%hi')       # field with non-alpha char
        self.assertRaises(ValueError, namedtuple, 'abc', 'abc class')      # field has keyword
        self.assertRaises(ValueError, namedtuple, 'abc', '8efg 9ghi')      # field starts with digit
        self.assertRaises(ValueError, namedtuple, 'abc', '__efg__ ghi')    # field with double underscores
        self.assertRaises(ValueError, namedtuple, 'abc', 'efg efg ghi')    # duplicate field

        namedtuple('Point0', 'x1 y2')   # Verify that numbers are allowed in names

    def test_instance(self):
        Point = namedtuple('Point', 'x y')
        p = Point(11, 22)
        self.assertEqual(p, Point(x=11, y=22))
        self.assertEqual(p, Point(11, y=22))
        self.assertEqual(p, Point(y=22, x=11))
        self.assertEqual(p, Point(*(11, 22)))
        self.assertEqual(p, Point(**dict(x=11, y=22)))
        self.assertRaises(TypeError, Point, 1)                              # too few args
        self.assertRaises(TypeError, Point, 1, 2, 3)                        # too many args
        self.assertRaises(TypeError, eval, 'Point(XXX=1, y=2)', locals())   # wrong keyword argument
        self.assertRaises(TypeError, eval, 'Point(x=1)', locals())          # missing keyword argument
        self.assertEqual(repr(p), 'Point(x=11, y=22)')
        self.assert_('__dict__' not in dir(p))                              # verify instance has no dict
        self.assert_('__weakref__' not in dir(p))
        self.assertEqual(p.__fields__, ('x', 'y'))                          # test __fields__ attribute
        self.assertEqual(p.__replace__(x=1), (1, 22))                       # test __replace__ method
        self.assertEqual(p.__asdict__(), dict(x=11, y=22))                  # test __dict__ method

        # Verify that __fields__ is read-only
        try:
            p.__fields__ = ('F1' ,'F2')
        except AttributeError:
            pass
        else:
            self.fail('The __fields__ attribute needs to be read-only')

        # verify that field string can have commas
        Point = namedtuple('Point', 'x, y')
        p = Point(x=11, y=22)
        self.assertEqual(repr(p), 'Point(x=11, y=22)')

        # verify that fieldspec can be a non-string sequence
        Point = namedtuple('Point', ('x', 'y'))
        p = Point(x=11, y=22)
        self.assertEqual(repr(p), 'Point(x=11, y=22)')

    def test_tupleness(self):
        Point = namedtuple('Point', 'x y')
        p = Point(11, 22)

        self.assert_(isinstance(p, tuple))
        self.assertEqual(p, (11, 22))                                       # matches a real tuple
        self.assertEqual(tuple(p), (11, 22))                                # coercable to a real tuple
        self.assertEqual(list(p), [11, 22])                                 # coercable to a list
        self.assertEqual(max(p), 22)                                        # iterable
        self.assertEqual(max(*p), 22)                                       # star-able
        x, y = p
        self.assertEqual(p, (x, y))                                         # unpacks like a tuple
        self.assertEqual((p[0], p[1]), (11, 22))                            # indexable like a tuple
        self.assertRaises(IndexError, p.__getitem__, 3)

        self.assertEqual(p.x, x)
        self.assertEqual(p.y, y)
        self.assertRaises(AttributeError, eval, 'p.z', locals())

    def test_odd_sizes(self):
        Zero = namedtuple('Zero', '')
        self.assertEqual(Zero(), ())
        Dot = namedtuple('Dot', 'd')
        self.assertEqual(Dot(1), (1,))

def test_main(verbose=None):
    import collections as CollectionsModule
    test_classes = [TestNamedTuple]
    test_support.run_unittest(*test_classes)
    test_support.run_doctest(CollectionsModule, verbose)

if __name__ == "__main__":
    test_main(verbose=True)