import unittest from test.test_support import check_syntax_error, check_py3k_warnings, \ check_warnings, run_unittest class ScopeTests(unittest.TestCase): def testSimpleNesting(self): def make_adder(x): def adder(y): return x + y return adder inc = make_adder(1) plus10 = make_adder(10) self.assertEqual(inc(1), 2) self.assertEqual(plus10(-2), 8) def testExtraNesting(self): def make_adder2(x): def extra(): # check freevars passing through non-use scopes def adder(y): return x + y return adder return extra() inc = make_adder2(1) plus10 = make_adder2(10) self.assertEqual(inc(1), 2) self.assertEqual(plus10(-2), 8) def testSimpleAndRebinding(self): def make_adder3(x): def adder(y): return x + y x = x + 1 # check tracking of assignment to x in defining scope return adder inc = make_adder3(0) plus10 = make_adder3(9) self.assertEqual(inc(1), 2) self.assertEqual(plus10(-2), 8) def testNestingGlobalNoFree(self): def make_adder4(): # XXX add exta level of indirection def nest(): def nest(): def adder(y): return global_x + y # check that plain old globals work return adder return nest() return nest() global_x = 1 adder = make_adder4() self.assertEqual(adder(1), 2) global_x = 10 self.assertEqual(adder(-2), 8) def testNestingThroughClass(self): def make_adder5(x): class Adder: def __call__(self, y): return x + y return Adder() inc = make_adder5(1) plus10 = make_adder5(10) self.assertEqual(inc(1), 2) self.assertEqual(plus10(-2), 8) def testNestingPlusFreeRefToGlobal(self): def make_adder6(x): global global_nest_x def adder(y): return global_nest_x + y global_nest_x = x return adder inc = make_adder6(1) plus10 = make_adder6(10) self.assertEqual(inc(1), 11) # there's only one global self.assertEqual(plus10(-2), 8) def testNearestEnclosingScope(self): def f(x): def g(y): x = 42 # check that this masks binding in f() def h(z): return x + z return h return g(2) test_func = f(10) self.assertEqual(test_func(5), 47) def testMixedFreevarsAndCellvars(self): def identity(x): return x def f(x, y, z): def g(a, b, c): a = a + x # 3 def h(): # z * (4 + 9) # 3 * 13 return identity(z * (b + y)) y = c + z # 9 return h return g g = f(1, 2, 3) h = g(2, 4, 6) self.assertEqual(h(), 39) def testFreeVarInMethod(self): def test(): method_and_var = "var" class Test: def method_and_var(self): return "method" def test(self): return method_and_var def actual_global(self): return str("global") def str(self): return str(self) return Test() t = test() self.assertEqual(t.test(), "var") self.assertEqual(t.method_and_var(), "method") self.assertEqual(t.actual_global(), "global") method_and_var = "var" class Test: # this class is not nested, so the rules are different def method_and_var(self): return "method" def test(self): return method_and_var def actual_global(self): return str("global") def str(self): return str(self) t = Test() self.assertEqual(t.test(), "var") self.assertEqual(t.method_and_var(), "method") self.assertEqual(t.actual_global(), "global") def testRecursion(self): def f(x): def fact(n): if n == 0: return 1 else: return n * fact(n - 1) if x >= 0: return fact(x) else: raise ValueError, "x must be >= 0" self.assertEqual(f(6), 720) def testUnoptimizedNamespaces(self): check_syntax_error(self, """\ def unoptimized_clash1(strip): def f(s): from string import * return strip(s) # ambiguity: free or local return f """) check_syntax_error(self, """\ def unoptimized_clash2(): from string import * def f(s): return strip(s) # ambiguity: global or local return f """) check_syntax_error(self, """\ def unoptimized_clash2(): from string import * def g(): def f(s): return strip(s) # ambiguity: global or local return f """) # XXX could allow this for exec with const argument, but what's the point check_syntax_error(self, """\ def error(y): exec "a = 1" def f(x): return x + y return f """) check_syntax_error(self, """\ def f(x): def g(): return x del x # can't del name """) check_syntax_error(self, """\ def f(): def g(): from string import * return strip # global or local? """) # and verify a few cases that should work exec """ def noproblem1(): from string import * f = lambda x:x def noproblem2(): from string import * def f(x): return x + 1 def noproblem3(): from string import * def f(x): global y y = x """ def testLambdas(self): f1 = lambda x: lambda y: x + y inc = f1(1) plus10 = f1(10) self.assertEqual(inc(1), 2) self.assertEqual(plus10(5), 15) f2 = lambda x: (lambda : lambda y: x + y)() inc = f2(1) plus10 = f2(10) self.assertEqual(inc(1), 2) self.assertEqual(plus10(5), 15) f3 = lambda x: lambda y: global_x + y global_x = 1 inc = f3(None) self.assertEqual(inc(2), 3) f8 = lambda x, y, z: lambda a, b, c: lambda : z * (b + y) g = f8(1, 2, 3) h = g(2, 4, 6) self.assertEqual(h(), 18) def testUnboundLocal(self): def errorInOuter(): print y def inner(): return y y = 1 def errorInInner(): def inner(): return y inner() y = 1 self.assertRaises(UnboundLocalError, errorInOuter) self.assertRaises(NameError, errorInInner) # test for bug #1501934: incorrect LOAD/STORE_GLOBAL generation exec """ global_x = 1 def f(): global_x += 1 try: f() except UnboundLocalError: pass else: fail('scope of global_x not correctly determined') """ in {'fail': self.fail} def testComplexDefinitions(self): def makeReturner(*lst): def returner(): return lst return returner self.assertEqual(makeReturner(1,2,3)(), (1,2,3)) def makeReturner2(**kwargs): def returner(): return kwargs return returner self.assertEqual(makeReturner2(a=11)()['a'], 11) with check_py3k_warnings(("tuple parameter unpacking has been removed", SyntaxWarning)): exec """\ def makeAddPair((a, b)): def addPair((c, d)): return (a + c, b + d) return addPair """ in locals() self.assertEqual(makeAddPair((1, 2))((100, 200)), (101,202)) def testScopeOfGlobalStmt(self): # Examples posted by Samuele Pedroni to python-dev on 3/1/2001 exec """\ # I x = 7 def f(): x = 1 def g(): global x def i(): def h(): return x return h() return i() return g() self.assertEqual(f(), 7) self.assertEqual(x, 7) # II x = 7 def f(): x = 1 def g(): x = 2 def i(): def h(): return x return h() return i() return g() self.assertEqual(f(), 2) self.assertEqual(x, 7) # III x = 7 def f(): x = 1 def g(): global x x = 2 def i(): def h(): return x return h() return i() return g() self.assertEqual(f(), 2) self.assertEqual(x, 2) # IV x = 7 def f(): x = 3 def g(): global x x = 2 def i(): def h(): return x return h() return i() return g() self.assertEqual(f(), 2) self.assertEqual(x, 2) # XXX what about global statements in class blocks? # do they affect methods? x = 12 class Global: global x x = 13 def set(self, val): x = val def get(self): return x g = Global() self.assertEqual(g.get(), 13) g.set(15) self.assertEqual(g.get(), 13) """ def testLeaks(self): class Foo: count = 0 def __init__(self): Foo.count += 1 def __del__(self): Foo.count -= 1 def f1(): x = Foo() def f2(): return x f2() for i in range(100): f1() self.assertEqual(Foo.count, 0) def testClassAndGlobal(self): exec """\ def test(x): class Foo: global x def __call__(self, y): return x + y return Foo() x = 0 self.assertEqual(test(6)(2), 8) x = -1 self.assertEqual(test(3)(2), 5) looked_up_by_load_name = False class X: # Implicit globals inside classes are be looked up by LOAD_NAME, not # LOAD_GLOBAL. locals()['looked_up_by_load_name'] = True passed = looked_up_by_load_name self.assertTrue(X.passed) """ def testLocalsFunction(self): def f(x): def g(y): def h(z): return y + z w = x + y y += 3 return locals() return g d = f(2)(4) self.assertIn('h', d) del d['h'] self.assertEqual(d, {'x': 2, 'y': 7, 'w': 6}) def testLocalsClass(self): # This test verifies that calling locals() does not pollute # the local namespace of the class with free variables. Old # versions of Python had a bug, where a free variable being # passed through a class namespace would be inserted into # locals() by locals() or exec or a trace function. # # The real bug lies in frame code that copies variables # between fast locals and the locals dict, e.g. when executing # a trace function. def f(x): class C: x = 12 def m(self): return x locals() return C self.assertEqual(f(1).x, 12) def f(x): class C: y = x def m(self): return x z = list(locals()) return C varnames = f(1).z self.assertNotIn("x", varnames) self.assertIn("y", varnames) def testLocalsClass_WithTrace(self): # Issue23728: after the trace function returns, the locals() # dictionary is used to update all variables, this used to # include free variables. But in class statements, free # variables are not inserted... import sys sys.settrace(lambda a,b,c:None) try: x = 12 class C: def f(self): return x self.assertEquals(x, 12) # Used to raise UnboundLocalError finally: sys.settrace(None) def testBoundAndFree(self): # var is bound and free in class def f(x): class C: def m(self): return x a = x return C inst = f(3)() self.assertEqual(inst.a, inst.m()) def testInteractionWithTraceFunc(self): import sys def tracer(a,b,c): return tracer def adaptgetter(name, klass, getter): kind, des = getter if kind == 1: # AV happens when stepping from this line to next if des == "": des = "_%s__%s" % (klass.__name__, name) return lambda obj: getattr(obj, des) class TestClass: pass sys.settrace(tracer) adaptgetter("foo", TestClass, (1, "")) sys.settrace(None) self.assertRaises(TypeError, sys.settrace) def testEvalExecFreeVars(self): def f(x): return lambda: x + 1 g = f(3) self.assertRaises(TypeError, eval, g.func_code) try: exec g.func_code in {} except TypeError: pass else: self.fail("exec should have failed, because code contained free vars") def testListCompLocalVars(self): try: print bad except NameError: pass else: print "bad should not be defined" def x(): [bad for s in 'a b' for bad in s.split()] x() try: print bad except NameError: pass def testEvalFreeVars(self): def f(x): def g(): x eval("x + 1") return g f(4)() def testFreeingCell(self): # Test what happens when a finalizer accesses # the cell where the object was stored. class Special: def __del__(self): nestedcell_get() def f(): global nestedcell_get def nestedcell_get(): return c c = (Special(),) c = 2 f() # used to crash the interpreter... def testGlobalInParallelNestedFunctions(self): # A symbol table bug leaked the global statement from one # function to other nested functions in the same block. # This test verifies that a global statement in the first # function does not affect the second function. CODE = """def f(): y = 1 def g(): global y return y def h(): return y + 1 return g, h y = 9 g, h = f() result9 = g() result2 = h() """ local_ns = {} global_ns = {} exec CODE in local_ns, global_ns self.assertEqual(2, global_ns["result2"]) self.assertEqual(9, global_ns["result9"]) def test_main(): with check_warnings(("import \* only allowed at module level", SyntaxWarning)): run_unittest(ScopeTests) if __name__ == '__main__': test_main()