Lib/test/test_funcattrs.py

   1 from test_support import verbose, TestFailed, verify
   2 import types
   3
   4 class F:
   5     def a(self):
   6         pass
   7
   8 def b():
   9     'my docstring'
  10     pass
  11
  12 # setting attributes on functions
  13 try:
  14     b.publish
  15 except AttributeError: pass
  16 else: raise TestFailed, 'expected AttributeError'
  17
  18 if b.__dict__ <> {}:
  19     raise TestFailed, 'expected unassigned func.__dict__ to be {}'
  20
  21 b.publish = 1
  22 if b.publish <> 1:
  23     raise TestFailed, 'function attribute not set to expected value'
  24
  25 docstring = 'its docstring'
  26 b.__doc__ = docstring
  27 if b.__doc__ <> docstring:
  28     raise TestFailed, 'problem with setting __doc__ attribute'
  29
  30 if 'publish' not in dir(b):
  31     raise TestFailed, 'attribute not in dir()'
  32
  33 try:
  34     del b.__dict__
  35 except TypeError: pass
  36 else: raise TestFailed, 'del func.__dict__ expected TypeError'
  37
  38 b.publish = 1
  39 try:
  40     b.__dict__ = None
  41 except TypeError: pass
  42 else: raise TestFailed, 'func.__dict__ = None expected TypeError'
  43
  44 d = {'hello': 'world'}
  45 b.__dict__ = d
  46 if b.func_dict is not d:
  47     raise TestFailed, 'func.__dict__ assignment to dictionary failed'
  48 if b.hello <> 'world':
  49     raise TestFailed, 'attribute after func.__dict__ assignment failed'
  50
  51 f1 = F()
  52 f2 = F()
  53
  54 try:
  55     F.a.publish
  56 except AttributeError: pass
  57 else: raise TestFailed, 'expected AttributeError'
  58
  59 try:
  60     f1.a.publish
  61 except AttributeError: pass
  62 else: raise TestFailed, 'expected AttributeError'
  63
  64 # In Python 2.1 beta 1, we disallowed setting attributes on unbound methods
  65 # (it was already disallowed on bound methods).  See the PEP for details.
  66 try:
  67     F.a.publish = 1
  68 except (AttributeError, TypeError): pass
  69 else: raise TestFailed, 'expected AttributeError or TypeError'
  70
  71 # But setting it explicitly on the underlying function object is okay.
  72 F.a.im_func.publish = 1
  73
  74 if F.a.publish <> 1:
  75     raise TestFailed, 'unbound method attribute not set to expected value'
  76
  77 if f1.a.publish <> 1:
  78     raise TestFailed, 'bound method attribute access did not work'
  79
  80 if f2.a.publish <> 1:
  81     raise TestFailed, 'bound method attribute access did not work'
  82
  83 if 'publish' not in dir(F.a):
  84     raise TestFailed, 'attribute not in dir()'
  85
  86 try:
  87     f1.a.publish = 0
  88 except (AttributeError, TypeError): pass
  89 else: raise TestFailed, 'expected AttributeError or TypeError'
  90
  91 # See the comment above about the change in semantics for Python 2.1b1
  92 try:
  93     F.a.myclass = F
  94 except (AttributeError, TypeError): pass
  95 else: raise TestFailed, 'expected AttributeError or TypeError'
  96
  97 F.a.im_func.myclass = F
  98
  99 f1.a.myclass
 100 f2.a.myclass
 101 f1.a.myclass
 102 F.a.myclass
 103
 104 if f1.a.myclass is not f2.a.myclass or \
 105        f1.a.myclass is not F.a.myclass:
 106     raise TestFailed, 'attributes were not the same'
 107
 108 # try setting __dict__
 109 try:
 110     F.a.__dict__ = (1, 2, 3)
 111 except (AttributeError, TypeError): pass
 112 else: raise TestFailed, 'expected TypeError or AttributeError'
 113
 114 F.a.im_func.__dict__ = {'one': 11, 'two': 22, 'three': 33}
 115
 116 if f1.a.two <> 22:
 117     raise TestFailed, 'setting __dict__'
 118
 119 from UserDict import UserDict
 120 d = UserDict({'four': 44, 'five': 55})
 121
 122 try:
 123     F.a.__dict__ = d
 124 except (AttributeError, TypeError): pass
 125 else: raise TestFailed
 126
 127 if f2.a.one <> f1.a.one <> F.a.one <> 11:
 128     raise TestFailed
 129
 130 # im_func may not be a Python method!
 131 import new
 132 F.id = new.instancemethod(id, None, F)
 133
 134 eff = F()
 135 if eff.id() <> id(eff):
 136     raise TestFailed
 137
 138 try:
 139     F.id.foo
 140 except AttributeError: pass
 141 else: raise TestFailed
 142
 143 try:
 144     F.id.foo = 12
 145 except (AttributeError, TypeError): pass
 146 else: raise TestFailed
 147
 148 try:
 149     F.id.foo
 150 except AttributeError: pass
 151 else: raise TestFailed
 152
 153 try:
 154     eff.id.foo
 155 except AttributeError: pass
 156 else: raise TestFailed
 157
 158 try:
 159     eff.id.foo = 12
 160 except (AttributeError, TypeError): pass
 161 else: raise TestFailed
 162
 163 try:
 164     eff.id.foo
 165 except AttributeError: pass
 166 else: raise TestFailed
 167
 168 # Regression test for a crash in pre-2.1a1
 169 def another():
 170     pass
 171
 172 try:
 173     del another.__dict__
 174 except TypeError: pass
 175 else: raise TestFailed
 176
 177 try:
 178     del another.func_dict
 179 except TypeError: pass
 180 else: raise TestFailed
 181
 182 try:
 183     another.func_dict = None
 184 except TypeError: pass
 185 else: raise TestFailed
 186
 187 try:
 188     del another.bar
 189 except AttributeError: pass
 190 else: raise TestFailed
 191
 192 # This isn't specifically related to function attributes, but it does test a
 193 # core dump regression in funcobject.c
 194 del another.func_defaults
 195
 196 def foo():
 197     pass
 198
 199 def bar():
 200     pass
 201
 202 def temp():
 203     print 1
 204
 205 if foo==bar:
 206     raise TestFailed
 207
 208 d={}
 209 d[foo] = 1
 210
 211 foo.func_code = temp.func_code
 212
 213 d[foo]
 214
 215 # Test all predefined function attributes systematically
 216
 217 def cantset(obj, name, value):
 218     verify(hasattr(obj, name)) # Otherwise it's probably a typo
 219     try:
 220         setattr(obj, name, value)
 221     except (AttributeError, TypeError):
 222         pass
 223     else:
 224         raise TestFailed, "shouldn't be able to set %s to %r" % (name, value)
 225     try:
 226         delattr(obj, name)
 227     except (AttributeError, TypeError):
 228         pass
 229     else:
 230         raise TestFailed, "shouldn't be able to del %s" % name
 231
 232 def test_func_closure():
 233     a = 12
 234     def f(): print a
 235     c = f.func_closure
 236     verify(isinstance(c, tuple))
 237     verify(len(c) == 1)
 238     verify(c[0].__class__.__name__ == "cell") # don't have a type object handy
 239     cantset(f, "func_closure", c)
 240
 241 def test_func_doc():
 242     def f(): pass
 243     verify(f.__doc__ is None)
 244     verify(f.func_doc is None)
 245     f.__doc__ = "hello"
 246     verify(f.__doc__ == "hello")
 247     verify(f.func_doc == "hello")
 248     del f.__doc__
 249     verify(f.__doc__ is None)
 250     verify(f.func_doc is None)
 251     f.func_doc = "world"
 252     verify(f.__doc__ == "world")
 253     verify(f.func_doc == "world")
 254     del f.func_doc
 255     verify(f.func_doc is None)
 256     verify(f.__doc__ is None)
 257
 258 def test_func_globals():
 259     def f(): pass
 260     verify(f.func_globals is globals())
 261     cantset(f, "func_globals", globals())
 262
 263 def test_func_name():
 264     def f(): pass
 265     verify(f.__name__ == "f")
 266     verify(f.func_name == "f")
 267     cantset(f, "func_name", "f")
 268     cantset(f, "__name__", "f")
 269
 270 def test_func_code():
 271     def f(): pass
 272     def g(): print 12
 273     verify(type(f.func_code) is types.CodeType)
 274     f.func_code = g.func_code
 275     cantset(f, "func_code", None)
 276
 277 def test_func_defaults():
 278     def f(a, b): return (a, b)
 279     verify(f.func_defaults is None)
 280     f.func_defaults = (1, 2)
 281     verify(f.func_defaults == (1, 2))
 282     verify(f(10) == (10, 2))
 283     def g(a=1, b=2): return (a, b)
 284     verify(g.func_defaults == (1, 2))
 285     del g.func_defaults
 286     verify(g.func_defaults is None)
 287     try:
 288         g()
 289     except TypeError:
 290         pass
 291     else:
 292         raise TestFailed, "shouldn't be allowed to call g() w/o defaults"
 293
 294 def test_func_dict():
 295     def f(): pass
 296     a = f.__dict__
 297     b = f.func_dict
 298     verify(a == {})
 299     verify(a is b)
 300     f.hello = 'world'
 301     verify(a == {'hello': 'world'})
 302     verify(f.func_dict is a is f.__dict__)
 303     f.func_dict = {}
 304     verify(not hasattr(f, "hello"))
 305     f.__dict__ = {'world': 'hello'}
 306     verify(f.world == "hello")
 307     verify(f.__dict__ is f.func_dict == {'world': 'hello'})
 308     cantset(f, "func_dict", None)
 309     cantset(f, "__dict__", None)
 310
 311 def test_im_class():
 312     class C:
 313         def foo(self): pass
 314     verify(C.foo.im_class is C)
 315     verify(C().foo.im_class is C)
 316     cantset(C.foo, "im_class", C)
 317     cantset(C().foo, "im_class", C)
 318
 319 def test_im_func():
 320     def foo(self): pass
 321     class C:
 322         pass
 323     C.foo = foo
 324     verify(C.foo.im_func is foo)
 325     verify(C().foo.im_func is foo)
 326     cantset(C.foo, "im_func", foo)
 327     cantset(C().foo, "im_func", foo)
 328
 329 def test_im_self():
 330     class C:
 331         def foo(self): pass
 332     verify(C.foo.im_self is None)
 333     c = C()
 334     verify(c.foo.im_self is c)
 335     cantset(C.foo, "im_self", None)
 336     cantset(c.foo, "im_self", c)
 337
 338 def test_im_dict():
 339     class C:
 340         def foo(self): pass
 341         foo.bar = 42
 342     verify(C.foo.__dict__ == {'bar': 42})
 343     verify(C().foo.__dict__ == {'bar': 42})
 344     cantset(C.foo, "__dict__", C.foo.__dict__)
 345     cantset(C().foo, "__dict__", C.foo.__dict__)
 346
 347 def test_im_doc():
 348     class C:
 349         def foo(self): "hello"
 350     verify(C.foo.__doc__ == "hello")
 351     verify(C().foo.__doc__ == "hello")
 352     cantset(C.foo, "__doc__", "hello")
 353     cantset(C().foo, "__doc__", "hello")
 354
 355 def test_im_name():
 356     class C:
 357         def foo(self): pass
 358     verify(C.foo.__name__ == "foo")
 359     verify(C().foo.__name__ == "foo")
 360     cantset(C.foo, "__name__", "foo")
 361     cantset(C().foo, "__name__", "foo")
 362
 363 def testmore():
 364     test_func_closure()
 365     test_func_doc()
 366     test_func_globals()
 367     test_func_name()
 368     test_func_code()
 369     test_func_defaults()
 370     test_func_dict()
 371     # Tests for instance method attributes
 372     test_im_class()
 373     test_im_func()
 374     test_im_self()
 375     test_im_dict()
 376     test_im_doc()
 377     test_im_name()
 378
 379 testmore()