from test import test_support
import types
import unittest
class FuncAttrsTest(unittest.TestCase):
def setUp(self):
class F:
def a(self):
pass
def b():
return 3
self.f = F
self.fi = F()
self.b = b
def cannot_set_attr(self, obj, name, value, exceptions):
# Helper method for other tests.
try:
setattr(obj, name, value)
except exceptions:
pass
else:
self.fail("shouldn't be able to set %s to %r" % (name, value))
try:
delattr(obj, name)
except exceptions:
pass
else:
self.fail("shouldn't be able to del %s" % name)
class FunctionPropertiesTest(FuncAttrsTest):
# Include the external setUp method that is common to all tests
def test_module(self):
self.assertEqual(self.b.__module__, __name__)
def test_dir_includes_correct_attrs(self):
self.b.known_attr = 7
self.assertIn('known_attr', dir(self.b),
"set attributes not in dir listing of method")
# Test on underlying function object of method
self.f.a.im_func.known_attr = 7
self.assertIn('known_attr', dir(self.f.a),
"set attribute on unbound method implementation in "
"class not in dir")
self.assertIn('known_attr', dir(self.fi.a),
"set attribute on unbound method implementations, "
"should show up in next dir")
def test_duplicate_function_equality(self):
# Body of `duplicate' is the exact same as self.b
def duplicate():
'my docstring'
return 3
self.assertNotEqual(self.b, duplicate)
def test_copying_func_code(self):
def test(): pass
self.assertEqual(test(), None)
test.func_code = self.b.func_code
self.assertEqual(test(), 3) # self.b always returns 3, arbitrarily
def test_func_globals(self):
self.assertIs(self.b.func_globals, globals())
self.cannot_set_attr(self.b, 'func_globals', 2, TypeError)
def test_func_closure(self):
a = 12
def f(): print a
c = f.func_closure
self.assertIsInstance(c, tuple)
self.assertEqual(len(c), 1)
# don't have a type object handy
self.assertEqual(c[0].__class__.__name__, "cell")
self.cannot_set_attr(f, "func_closure", c, TypeError)
def test_empty_cell(self):
def f(): print a
try:
f.func_closure[0].cell_contents
except ValueError:
pass
else:
self.fail("shouldn't be able to read an empty cell")
a = 12
def test_func_name(self):
self.assertEqual(self.b.__name__, 'b')
self.assertEqual(self.b.func_name, 'b')
self.b.__name__ = 'c'
self.assertEqual(self.b.__name__, 'c')
self.assertEqual(self.b.func_name, 'c')
self.b.func_name = 'd'
self.assertEqual(self.b.__name__, 'd')
self.assertEqual(self.b.func_name, 'd')
# __name__ and func_name must be a string
self.cannot_set_attr(self.b, '__name__', 7, TypeError)
self.cannot_set_attr(self.b, 'func_name', 7, TypeError)
# __name__ must be available when in restricted mode. Exec will raise
# AttributeError if __name__ is not available on f.
s = """def f(): pass\nf.__name__"""
exec s in {'__builtins__': {}}
# Test on methods, too
self.assertEqual(self.f.a.__name__, 'a')
self.assertEqual(self.fi.a.__name__, 'a')
self.cannot_set_attr(self.f.a, "__name__", 'a', AttributeError)
self.cannot_set_attr(self.fi.a, "__name__", 'a', AttributeError)
def test_func_code(self):
num_one, num_two = 7, 8
def a(): pass
def b(): return 12
def c(): return num_one
def d(): return num_two
def e(): return num_one, num_two
for func in [a, b, c, d, e]:
self.assertEqual(type(func.func_code), types.CodeType)
self.assertEqual(c(), 7)
self.assertEqual(d(), 8)
d.func_code = c.func_code
self.assertEqual(c.func_code, d.func_code)
self.assertEqual(c(), 7)
# self.assertEqual(d(), 7)
try:
b.func_code = c.func_code
except ValueError:
pass
else:
self.fail("func_code with different numbers of free vars should "
"not be possible")
try:
e.func_code = d.func_code
except ValueError:
pass
else:
self.fail("func_code with different numbers of free vars should "
"not be possible")
def test_blank_func_defaults(self):
self.assertEqual(self.b.func_defaults, None)
del self.b.func_defaults
self.assertEqual(self.b.func_defaults, None)
def test_func_default_args(self):
def first_func(a, b):
return a+b
def second_func(a=1, b=2):
return a+b
self.assertEqual(first_func.func_defaults, None)
self.assertEqual(second_func.func_defaults, (1, 2))
first_func.func_defaults = (1, 2)
self.assertEqual(first_func.func_defaults, (1, 2))
self.assertEqual(first_func(), 3)
self.assertEqual(first_func(3), 5)
self.assertEqual(first_func(3, 5), 8)
del second_func.func_defaults
self.assertEqual(second_func.func_defaults, None)
try:
second_func()
except TypeError:
pass
else:
self.fail("func_defaults does not update; deleting it does not "
"remove requirement")
class InstancemethodAttrTest(FuncAttrsTest):
def test_im_class(self):
self.assertEqual(self.f.a.im_class, self.f)
self.assertEqual(self.fi.a.im_class, self.f)
self.cannot_set_attr(self.f.a, "im_class", self.f, TypeError)
self.cannot_set_attr(self.fi.a, "im_class", self.f, TypeError)
def test_im_func(self):
self.f.b = self.b
self.assertEqual(self.f.b.im_func, self.b)
self.assertEqual(self.fi.b.im_func, self.b)
self.cannot_set_attr(self.f.b, "im_func", self.b, TypeError)
self.cannot_set_attr(self.fi.b, "im_func", self.b, TypeError)
def test_im_self(self):
self.assertEqual(self.f.a.im_self, None)
self.assertEqual(self.fi.a.im_self, self.fi)
self.cannot_set_attr(self.f.a, "im_self", None, TypeError)
self.cannot_set_attr(self.fi.a, "im_self", self.fi, TypeError)
def test_im_func_non_method(self):
# Behavior should be the same when a method is added via an attr
# assignment
self.f.id = types.MethodType(id, None, self.f)
self.assertEqual(self.fi.id(), id(self.fi))
self.assertNotEqual(self.fi.id(), id(self.f))
# Test usage
try:
self.f.id.unknown_attr
except AttributeError:
pass
else:
self.fail("using unknown attributes should raise AttributeError")
# Test assignment and deletion
self.cannot_set_attr(self.f.id, 'unknown_attr', 2, AttributeError)
self.cannot_set_attr(self.fi.id, 'unknown_attr', 2, AttributeError)
def test_implicit_method_properties(self):
self.f.a.im_func.known_attr = 7
self.assertEqual(self.f.a.known_attr, 7)
self.assertEqual(self.fi.a.known_attr, 7)
class ArbitraryFunctionAttrTest(FuncAttrsTest):
def test_set_attr(self):
# setting attributes only works on function objects
self.b.known_attr = 7
self.assertEqual(self.b.known_attr, 7)
for func in [self.f.a, self.fi.a]:
try:
func.known_attr = 7
except AttributeError:
pass
else:
self.fail("setting attributes on methods should raise error")
def test_delete_unknown_attr(self):
try:
del self.b.unknown_attr
except AttributeError:
pass
else:
self.fail("deleting unknown attribute should raise TypeError")
def test_setting_attrs_duplicates(self):
try:
self.f.a.klass = self.f
except AttributeError:
pass
else:
self.fail("setting arbitrary attribute in unbound function "
" should raise AttributeError")
self.f.a.im_func.klass = self.f
for method in [self.f.a, self.fi.a, self.fi.a.im_func]:
self.assertEqual(method.klass, self.f)
def test_unset_attr(self):
for func in [self.b, self.f.a, self.fi.a]:
try:
func.non_existent_attr
except AttributeError:
pass
else:
self.fail("using unknown attributes should raise "
"AttributeError")
class FunctionDictsTest(FuncAttrsTest):
def test_setting_dict_to_invalid(self):
self.cannot_set_attr(self.b, '__dict__', None, TypeError)
self.cannot_set_attr(self.b, 'func_dict', None, TypeError)
from UserDict import UserDict
d = UserDict({'known_attr': 7})
self.cannot_set_attr(self.f.a.im_func, '__dict__', d, TypeError)
self.cannot_set_attr(self.fi.a.im_func, '__dict__', d, TypeError)
def test_setting_dict_to_valid(self):
d = {'known_attr': 7}
self.b.__dict__ = d
# Setting dict is only possible on the underlying function objects
self.f.a.im_func.__dict__ = d
# Test assignment
self.assertIs(d, self.b.__dict__)
self.assertIs(d, self.b.func_dict)
# ... and on all the different ways of referencing the method's func
self.assertIs(d, self.f.a.im_func.__dict__)
self.assertIs(d, self.f.a.__dict__)
self.assertIs(d, self.fi.a.im_func.__dict__)
self.assertIs(d, self.fi.a.__dict__)
# Test value
self.assertEqual(self.b.known_attr, 7)
self.assertEqual(self.b.__dict__['known_attr'], 7)
self.assertEqual(self.b.func_dict['known_attr'], 7)
# ... and again, on all the different method's names
self.assertEqual(self.f.a.im_func.known_attr, 7)
self.assertEqual(self.f.a.known_attr, 7)
self.assertEqual(self.fi.a.im_func.known_attr, 7)
self.assertEqual(self.fi.a.known_attr, 7)
def test_delete_func_dict(self):
try:
del self.b.__dict__
except TypeError:
pass
else:
self.fail("deleting function dictionary should raise TypeError")
try:
del self.b.func_dict
except TypeError:
pass
else:
self.fail("deleting function dictionary should raise TypeError")
def test_unassigned_dict(self):
self.assertEqual(self.b.__dict__, {})
def test_func_as_dict_key(self):
value = "Some string"
d = {}
d[self.b] = value
self.assertEqual(d[self.b], value)
class FunctionDocstringTest(FuncAttrsTest):
def test_set_docstring_attr(self):
self.assertEqual(self.b.__doc__, None)
self.assertEqual(self.b.func_doc, None)
docstr = "A test method that does nothing"
self.b.__doc__ = self.f.a.im_func.__doc__ = docstr
self.assertEqual(self.b.__doc__, docstr)
self.assertEqual(self.b.func_doc, docstr)
self.assertEqual(self.f.a.__doc__, docstr)
self.assertEqual(self.fi.a.__doc__, docstr)
self.cannot_set_attr(self.f.a, "__doc__", docstr, AttributeError)
self.cannot_set_attr(self.fi.a, "__doc__", docstr, AttributeError)
def test_delete_docstring(self):
self.b.__doc__ = "The docstring"
del self.b.__doc__
self.assertEqual(self.b.__doc__, None)
self.assertEqual(self.b.func_doc, None)
self.b.func_doc = "The docstring"
del self.b.func_doc
self.assertEqual(self.b.__doc__, None)
self.assertEqual(self.b.func_doc, None)
class StaticMethodAttrsTest(unittest.TestCase):
def test_func_attribute(self):
def f():
pass
c = classmethod(f)
self.assertTrue(c.__func__ is f)
s = staticmethod(f)
self.assertTrue(s.__func__ is f)
def test_main():
test_support.run_unittest(FunctionPropertiesTest, InstancemethodAttrTest,
ArbitraryFunctionAttrTest, FunctionDictsTest,
FunctionDocstringTest,
StaticMethodAttrsTest)
if __name__ == "__main__":
test_main()