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f37708e048
svn+ssh://pythondev@svn.python.org/python/trunk The merge ran into a lot of conflicts because dicts were replaced with sets in the Python 3 version of the symbol table. ........ r70801 | jeremy.hylton | 2009-03-31 09:17:03 -0400 (Tue, 31 Mar 2009) | 3 lines Add is_declared_global() which distinguishes between implicit and explicit global variables. ........ r70809 | jeremy.hylton | 2009-03-31 09:48:15 -0400 (Tue, 31 Mar 2009) | 14 lines Global statements from one function leaked into parallel functions. Re http://bugs.python.org/issue4315 The symbol table used the same name dictionaries to recursively analyze each of its child blocks, even though the dictionaries are modified during analysis. The fix is to create new temporary dictionaries via the analyze_child_block(). The only information that needs to propagate back up is the names of the free variables. Add more comments and break out a helper function. This code doesn't get any easier to understand when you only look at it once a year. ........
713 lines
16 KiB
Python
713 lines
16 KiB
Python
import unittest
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from test.support import check_syntax_error, run_unittest
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import warnings
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warnings.filterwarnings("ignore", r"import \*", SyntaxWarning, "<test string>")
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warnings.filterwarnings("ignore", r"import \*", SyntaxWarning, "<string>")
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class ScopeTests(unittest.TestCase):
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def testSimpleNesting(self):
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def make_adder(x):
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def adder(y):
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return x + y
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return adder
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inc = make_adder(1)
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plus10 = make_adder(10)
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self.assertEqual(inc(1), 2)
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self.assertEqual(plus10(-2), 8)
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def testExtraNesting(self):
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def make_adder2(x):
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def extra(): # check freevars passing through non-use scopes
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def adder(y):
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return x + y
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return adder
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return extra()
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inc = make_adder2(1)
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plus10 = make_adder2(10)
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self.assertEqual(inc(1), 2)
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self.assertEqual(plus10(-2), 8)
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def testSimpleAndRebinding(self):
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def make_adder3(x):
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def adder(y):
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return x + y
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x = x + 1 # check tracking of assignment to x in defining scope
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return adder
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inc = make_adder3(0)
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plus10 = make_adder3(9)
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self.assertEqual(inc(1), 2)
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self.assertEqual(plus10(-2), 8)
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def testNestingGlobalNoFree(self):
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def make_adder4(): # XXX add exta level of indirection
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def nest():
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def nest():
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def adder(y):
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return global_x + y # check that plain old globals work
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return adder
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return nest()
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return nest()
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global_x = 1
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adder = make_adder4()
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self.assertEqual(adder(1), 2)
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global_x = 10
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self.assertEqual(adder(-2), 8)
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def testNestingThroughClass(self):
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def make_adder5(x):
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class Adder:
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def __call__(self, y):
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return x + y
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return Adder()
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inc = make_adder5(1)
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plus10 = make_adder5(10)
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self.assertEqual(inc(1), 2)
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self.assertEqual(plus10(-2), 8)
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def testNestingPlusFreeRefToGlobal(self):
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def make_adder6(x):
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global global_nest_x
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def adder(y):
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return global_nest_x + y
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global_nest_x = x
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return adder
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inc = make_adder6(1)
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plus10 = make_adder6(10)
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self.assertEqual(inc(1), 11) # there's only one global
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self.assertEqual(plus10(-2), 8)
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def testNearestEnclosingScope(self):
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def f(x):
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def g(y):
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x = 42 # check that this masks binding in f()
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def h(z):
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return x + z
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return h
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return g(2)
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test_func = f(10)
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self.assertEqual(test_func(5), 47)
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def testMixedFreevarsAndCellvars(self):
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def identity(x):
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return x
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def f(x, y, z):
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def g(a, b, c):
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a = a + x # 3
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def h():
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# z * (4 + 9)
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# 3 * 13
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return identity(z * (b + y))
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y = c + z # 9
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return h
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return g
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g = f(1, 2, 3)
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h = g(2, 4, 6)
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self.assertEqual(h(), 39)
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def testFreeVarInMethod(self):
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def test():
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method_and_var = "var"
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class Test:
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def method_and_var(self):
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return "method"
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def test(self):
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return method_and_var
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def actual_global(self):
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return str("global")
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def str(self):
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return str(self)
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return Test()
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t = test()
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self.assertEqual(t.test(), "var")
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self.assertEqual(t.method_and_var(), "method")
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self.assertEqual(t.actual_global(), "global")
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method_and_var = "var"
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class Test:
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# this class is not nested, so the rules are different
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def method_and_var(self):
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return "method"
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def test(self):
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return method_and_var
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def actual_global(self):
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return str("global")
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def str(self):
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return str(self)
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t = Test()
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self.assertEqual(t.test(), "var")
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self.assertEqual(t.method_and_var(), "method")
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self.assertEqual(t.actual_global(), "global")
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def testCellIsKwonlyArg(self):
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# Issue 1409: Initialisation of a cell value,
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# when it comes from a keyword-only parameter
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def foo(*, a=17):
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def bar():
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return a + 5
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return bar() + 3
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self.assertEqual(foo(a=42), 50)
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self.assertEqual(foo(), 25)
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def testRecursion(self):
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def f(x):
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def fact(n):
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if n == 0:
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return 1
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else:
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return n * fact(n - 1)
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if x >= 0:
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return fact(x)
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else:
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raise ValueError("x must be >= 0")
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self.assertEqual(f(6), 720)
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def testUnoptimizedNamespaces(self):
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check_syntax_error(self, """\
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def unoptimized_clash1(strip):
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def f(s):
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from sys import *
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return getrefcount(s) # ambiguity: free or local
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return f
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""")
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check_syntax_error(self, """\
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def unoptimized_clash2():
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from sys import *
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def f(s):
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return getrefcount(s) # ambiguity: global or local
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return f
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""")
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check_syntax_error(self, """\
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def unoptimized_clash2():
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from sys import *
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def g():
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def f(s):
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return getrefcount(s) # ambiguity: global or local
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return f
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""")
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check_syntax_error(self, """\
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def f(x):
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def g():
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return x
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del x # can't del name
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""")
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check_syntax_error(self, """\
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def f():
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def g():
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from sys import *
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return getrefcount # global or local?
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""")
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def testLambdas(self):
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f1 = lambda x: lambda y: x + y
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inc = f1(1)
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plus10 = f1(10)
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self.assertEqual(inc(1), 2)
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self.assertEqual(plus10(5), 15)
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f2 = lambda x: (lambda : lambda y: x + y)()
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inc = f2(1)
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plus10 = f2(10)
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self.assertEqual(inc(1), 2)
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self.assertEqual(plus10(5), 15)
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f3 = lambda x: lambda y: global_x + y
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global_x = 1
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inc = f3(None)
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self.assertEqual(inc(2), 3)
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f8 = lambda x, y, z: lambda a, b, c: lambda : z * (b + y)
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g = f8(1, 2, 3)
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h = g(2, 4, 6)
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self.assertEqual(h(), 18)
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def testUnboundLocal(self):
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def errorInOuter():
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print(y)
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def inner():
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return y
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y = 1
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def errorInInner():
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def inner():
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return y
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inner()
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y = 1
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try:
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errorInOuter()
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except UnboundLocalError:
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pass
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else:
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self.fail()
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try:
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errorInInner()
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except NameError:
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pass
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else:
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self.fail()
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# test for bug #1501934: incorrect LOAD/STORE_GLOBAL generation
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exec("""
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global_x = 1
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def f():
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global_x += 1
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try:
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f()
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except UnboundLocalError:
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pass
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else:
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fail('scope of global_x not correctly determined')
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""", {'fail': self.fail})
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def testComplexDefinitions(self):
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def makeReturner(*lst):
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def returner():
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return lst
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return returner
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self.assertEqual(makeReturner(1,2,3)(), (1,2,3))
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def makeReturner2(**kwargs):
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def returner():
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return kwargs
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return returner
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self.assertEqual(makeReturner2(a=11)()['a'], 11)
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def testScopeOfGlobalStmt(self):
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# Examples posted by Samuele Pedroni to python-dev on 3/1/2001
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exec("""\
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# I
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x = 7
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def f():
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x = 1
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def g():
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global x
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def i():
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def h():
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return x
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return h()
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return i()
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return g()
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self.assertEqual(f(), 7)
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self.assertEqual(x, 7)
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# II
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x = 7
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def f():
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x = 1
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def g():
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x = 2
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def i():
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def h():
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return x
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return h()
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return i()
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return g()
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self.assertEqual(f(), 2)
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self.assertEqual(x, 7)
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# III
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x = 7
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def f():
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x = 1
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def g():
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global x
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x = 2
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def i():
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def h():
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return x
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return h()
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return i()
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return g()
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self.assertEqual(f(), 2)
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self.assertEqual(x, 2)
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# IV
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x = 7
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def f():
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x = 3
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def g():
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global x
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x = 2
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def i():
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def h():
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return x
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return h()
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return i()
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return g()
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self.assertEqual(f(), 2)
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self.assertEqual(x, 2)
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# XXX what about global statements in class blocks?
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# do they affect methods?
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x = 12
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class Global:
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global x
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x = 13
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def set(self, val):
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x = val
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def get(self):
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return x
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g = Global()
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self.assertEqual(g.get(), 13)
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g.set(15)
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self.assertEqual(g.get(), 13)
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""")
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def testLeaks(self):
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class Foo:
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count = 0
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def __init__(self):
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Foo.count += 1
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def __del__(self):
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Foo.count -= 1
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def f1():
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x = Foo()
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def f2():
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return x
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f2()
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for i in range(100):
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f1()
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self.assertEqual(Foo.count, 0)
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def testClassAndGlobal(self):
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exec("""\
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def test(x):
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class Foo:
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global x
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def __call__(self, y):
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return x + y
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return Foo()
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x = 0
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self.assertEqual(test(6)(2), 8)
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x = -1
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self.assertEqual(test(3)(2), 5)
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looked_up_by_load_name = False
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class X:
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# Implicit globals inside classes are be looked up by LOAD_NAME, not
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# LOAD_GLOBAL.
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locals()['looked_up_by_load_name'] = True
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passed = looked_up_by_load_name
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self.assert_(X.passed)
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""")
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def testLocalsFunction(self):
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def f(x):
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def g(y):
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def h(z):
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return y + z
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w = x + y
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y += 3
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return locals()
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return g
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d = f(2)(4)
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self.assert_('h' in d)
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del d['h']
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self.assertEqual(d, {'x': 2, 'y': 7, 'w': 6})
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def testLocalsClass(self):
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# This test verifies that calling locals() does not pollute
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# the local namespace of the class with free variables. Old
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# versions of Python had a bug, where a free variable being
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# passed through a class namespace would be inserted into
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# locals() by locals() or exec or a trace function.
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#
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# The real bug lies in frame code that copies variables
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# between fast locals and the locals dict, e.g. when executing
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# a trace function.
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def f(x):
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class C:
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x = 12
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def m(self):
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return x
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locals()
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return C
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self.assertEqual(f(1).x, 12)
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def f(x):
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class C:
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y = x
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def m(self):
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return x
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z = list(locals())
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return C
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varnames = f(1).z
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self.assert_("x" not in varnames)
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self.assert_("y" in varnames)
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def testLocalsClass_WithTrace(self):
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# Issue23728: after the trace function returns, the locals()
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# dictionary is used to update all variables, this used to
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# include free variables. But in class statements, free
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# variables are not inserted...
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import sys
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sys.settrace(lambda a,b,c:None)
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try:
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x = 12
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class C:
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def f(self):
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return x
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self.assertEquals(x, 12) # Used to raise UnboundLocalError
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finally:
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sys.settrace(None)
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def testBoundAndFree(self):
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# var is bound and free in class
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def f(x):
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class C:
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def m(self):
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return x
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a = x
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return C
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inst = f(3)()
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self.assertEqual(inst.a, inst.m())
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def testInteractionWithTraceFunc(self):
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import sys
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def tracer(a,b,c):
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return tracer
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def adaptgetter(name, klass, getter):
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kind, des = getter
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if kind == 1: # AV happens when stepping from this line to next
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if des == "":
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des = "_%s__%s" % (klass.__name__, name)
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return lambda obj: getattr(obj, des)
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class TestClass:
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pass
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sys.settrace(tracer)
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adaptgetter("foo", TestClass, (1, ""))
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sys.settrace(None)
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self.assertRaises(TypeError, sys.settrace)
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def testEvalExecFreeVars(self):
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def f(x):
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return lambda: x + 1
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g = f(3)
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self.assertRaises(TypeError, eval, g.__code__)
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try:
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exec(g.__code__, {})
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except TypeError:
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pass
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else:
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self.fail("exec should have failed, because code contained free vars")
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def testListCompLocalVars(self):
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try:
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print(bad)
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except NameError:
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pass
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else:
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print("bad should not be defined")
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def x():
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[bad for s in 'a b' for bad in s.split()]
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x()
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try:
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print(bad)
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except NameError:
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pass
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def testEvalFreeVars(self):
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def f(x):
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def g():
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x
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eval("x + 1")
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return g
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f(4)()
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def testFreeingCell(self):
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# Test what happens when a finalizer accesses
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# the cell where the object was stored.
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class Special:
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def __del__(self):
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nestedcell_get()
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def testNonLocalFunction(self):
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def f(x):
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def inc():
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nonlocal x
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x += 1
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return x
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def dec():
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nonlocal x
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x -= 1
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return x
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return inc, dec
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inc, dec = f(0)
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self.assertEqual(inc(), 1)
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self.assertEqual(inc(), 2)
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self.assertEqual(dec(), 1)
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self.assertEqual(dec(), 0)
|
|
|
|
def testNonLocalMethod(self):
|
|
def f(x):
|
|
class c:
|
|
def inc(self):
|
|
nonlocal x
|
|
x += 1
|
|
return x
|
|
def dec(self):
|
|
nonlocal x
|
|
x -= 1
|
|
return x
|
|
return c()
|
|
c = f(0)
|
|
self.assertEqual(c.inc(), 1)
|
|
self.assertEqual(c.inc(), 2)
|
|
self.assertEqual(c.dec(), 1)
|
|
self.assertEqual(c.dec(), 0)
|
|
|
|
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, local_ns, global_ns)
|
|
self.assertEqual(2, global_ns["result2"])
|
|
self.assertEqual(9, global_ns["result9"])
|
|
|
|
def testNonLocalClass(self):
|
|
|
|
def f(x):
|
|
class c:
|
|
nonlocal x
|
|
x += 1
|
|
def get(self):
|
|
return x
|
|
return c()
|
|
|
|
c = f(0)
|
|
self.assertEqual(c.get(), 1)
|
|
self.assert_("x" not in c.__class__.__dict__)
|
|
|
|
|
|
def testNonLocalGenerator(self):
|
|
|
|
def f(x):
|
|
def g(y):
|
|
nonlocal x
|
|
for i in range(y):
|
|
x += 1
|
|
yield x
|
|
return g
|
|
|
|
g = f(0)
|
|
self.assertEqual(list(g(5)), [1, 2, 3, 4, 5])
|
|
|
|
def testNestedNonLocal(self):
|
|
|
|
def f(x):
|
|
def g():
|
|
nonlocal x
|
|
x -= 2
|
|
def h():
|
|
nonlocal x
|
|
x += 4
|
|
return x
|
|
return h
|
|
return g
|
|
|
|
g = f(1)
|
|
h = g()
|
|
self.assertEqual(h(), 3)
|
|
|
|
|
|
def test_main():
|
|
run_unittest(ScopeTests)
|
|
|
|
if __name__ == '__main__':
|
|
test_main()
|