1 | import unittest |
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2 | from test.test_support import check_syntax_error, check_py3k_warnings, \ |
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3 | check_warnings, run_unittest |
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4 | |
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5 | |
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6 | class ScopeTests(unittest.TestCase): |
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7 | |
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8 | def testSimpleNesting(self): |
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9 | |
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10 | def make_adder(x): |
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11 | def adder(y): |
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12 | return x + y |
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13 | return adder |
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14 | |
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15 | inc = make_adder(1) |
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16 | plus10 = make_adder(10) |
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17 | |
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18 | self.assertEqual(inc(1), 2) |
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19 | self.assertEqual(plus10(-2), 8) |
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20 | |
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21 | def testExtraNesting(self): |
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22 | |
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23 | def make_adder2(x): |
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24 | def extra(): # check freevars passing through non-use scopes |
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25 | def adder(y): |
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26 | return x + y |
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27 | return adder |
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28 | return extra() |
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29 | |
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30 | inc = make_adder2(1) |
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31 | plus10 = make_adder2(10) |
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32 | |
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33 | self.assertEqual(inc(1), 2) |
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34 | self.assertEqual(plus10(-2), 8) |
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35 | |
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36 | def testSimpleAndRebinding(self): |
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37 | |
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38 | def make_adder3(x): |
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39 | def adder(y): |
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40 | return x + y |
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41 | x = x + 1 # check tracking of assignment to x in defining scope |
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42 | return adder |
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43 | |
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44 | inc = make_adder3(0) |
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45 | plus10 = make_adder3(9) |
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46 | |
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47 | self.assertEqual(inc(1), 2) |
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48 | self.assertEqual(plus10(-2), 8) |
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49 | |
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50 | def testNestingGlobalNoFree(self): |
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51 | |
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52 | def make_adder4(): # XXX add exta level of indirection |
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53 | def nest(): |
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54 | def nest(): |
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55 | def adder(y): |
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56 | return global_x + y # check that plain old globals work |
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57 | return adder |
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58 | return nest() |
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59 | return nest() |
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60 | |
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61 | global_x = 1 |
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62 | adder = make_adder4() |
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63 | self.assertEqual(adder(1), 2) |
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64 | |
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65 | global_x = 10 |
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66 | self.assertEqual(adder(-2), 8) |
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67 | |
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68 | def testNestingThroughClass(self): |
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69 | |
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70 | def make_adder5(x): |
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71 | class Adder: |
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72 | def __call__(self, y): |
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73 | return x + y |
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74 | return Adder() |
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75 | |
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76 | inc = make_adder5(1) |
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77 | plus10 = make_adder5(10) |
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78 | |
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79 | self.assertEqual(inc(1), 2) |
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80 | self.assertEqual(plus10(-2), 8) |
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81 | |
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82 | def testNestingPlusFreeRefToGlobal(self): |
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83 | |
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84 | def make_adder6(x): |
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85 | global global_nest_x |
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86 | def adder(y): |
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87 | return global_nest_x + y |
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88 | global_nest_x = x |
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89 | return adder |
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90 | |
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91 | inc = make_adder6(1) |
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92 | plus10 = make_adder6(10) |
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93 | |
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94 | self.assertEqual(inc(1), 11) # there's only one global |
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95 | self.assertEqual(plus10(-2), 8) |
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96 | |
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97 | def testNearestEnclosingScope(self): |
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98 | |
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99 | def f(x): |
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100 | def g(y): |
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101 | x = 42 # check that this masks binding in f() |
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102 | def h(z): |
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103 | return x + z |
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104 | return h |
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105 | return g(2) |
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106 | |
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107 | test_func = f(10) |
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108 | self.assertEqual(test_func(5), 47) |
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109 | |
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110 | def testMixedFreevarsAndCellvars(self): |
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111 | |
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112 | def identity(x): |
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113 | return x |
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114 | |
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115 | def f(x, y, z): |
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116 | def g(a, b, c): |
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117 | a = a + x # 3 |
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118 | def h(): |
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119 | # z * (4 + 9) |
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120 | # 3 * 13 |
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121 | return identity(z * (b + y)) |
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122 | y = c + z # 9 |
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123 | return h |
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124 | return g |
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125 | |
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126 | g = f(1, 2, 3) |
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127 | h = g(2, 4, 6) |
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128 | self.assertEqual(h(), 39) |
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129 | |
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130 | def testFreeVarInMethod(self): |
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131 | |
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132 | def test(): |
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133 | method_and_var = "var" |
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134 | class Test: |
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135 | def method_and_var(self): |
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136 | return "method" |
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137 | def test(self): |
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138 | return method_and_var |
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139 | def actual_global(self): |
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140 | return str("global") |
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141 | def str(self): |
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142 | return str(self) |
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143 | return Test() |
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144 | |
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145 | t = test() |
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146 | self.assertEqual(t.test(), "var") |
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147 | self.assertEqual(t.method_and_var(), "method") |
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148 | self.assertEqual(t.actual_global(), "global") |
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149 | |
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150 | method_and_var = "var" |
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151 | class Test: |
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152 | # this class is not nested, so the rules are different |
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153 | def method_and_var(self): |
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154 | return "method" |
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155 | def test(self): |
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156 | return method_and_var |
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157 | def actual_global(self): |
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158 | return str("global") |
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159 | def str(self): |
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160 | return str(self) |
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161 | |
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162 | t = Test() |
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163 | self.assertEqual(t.test(), "var") |
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164 | self.assertEqual(t.method_and_var(), "method") |
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165 | self.assertEqual(t.actual_global(), "global") |
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166 | |
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167 | def testRecursion(self): |
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168 | |
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169 | def f(x): |
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170 | def fact(n): |
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171 | if n == 0: |
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172 | return 1 |
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173 | else: |
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174 | return n * fact(n - 1) |
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175 | if x >= 0: |
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176 | return fact(x) |
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177 | else: |
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178 | raise ValueError, "x must be >= 0" |
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179 | |
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180 | self.assertEqual(f(6), 720) |
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181 | |
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182 | |
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183 | def testUnoptimizedNamespaces(self): |
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184 | |
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185 | check_syntax_error(self, """\ |
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186 | def unoptimized_clash1(strip): |
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187 | def f(s): |
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188 | from string import * |
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189 | return strip(s) # ambiguity: free or local |
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190 | return f |
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191 | """) |
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192 | |
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193 | check_syntax_error(self, """\ |
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194 | def unoptimized_clash2(): |
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195 | from string import * |
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196 | def f(s): |
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197 | return strip(s) # ambiguity: global or local |
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198 | return f |
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199 | """) |
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200 | |
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201 | check_syntax_error(self, """\ |
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202 | def unoptimized_clash2(): |
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203 | from string import * |
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204 | def g(): |
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205 | def f(s): |
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206 | return strip(s) # ambiguity: global or local |
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207 | return f |
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208 | """) |
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209 | |
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210 | # XXX could allow this for exec with const argument, but what's the point |
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211 | check_syntax_error(self, """\ |
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212 | def error(y): |
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213 | exec "a = 1" |
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214 | def f(x): |
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215 | return x + y |
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216 | return f |
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217 | """) |
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218 | |
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219 | check_syntax_error(self, """\ |
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220 | def f(x): |
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221 | def g(): |
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222 | return x |
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223 | del x # can't del name |
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224 | """) |
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225 | |
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226 | check_syntax_error(self, """\ |
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227 | def f(): |
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228 | def g(): |
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229 | from string import * |
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230 | return strip # global or local? |
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231 | """) |
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232 | |
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233 | # and verify a few cases that should work |
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234 | |
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235 | exec """ |
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236 | def noproblem1(): |
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237 | from string import * |
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238 | f = lambda x:x |
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239 | |
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240 | def noproblem2(): |
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241 | from string import * |
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242 | def f(x): |
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243 | return x + 1 |
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244 | |
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245 | def noproblem3(): |
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246 | from string import * |
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247 | def f(x): |
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248 | global y |
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249 | y = x |
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250 | """ |
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251 | |
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252 | def testLambdas(self): |
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253 | |
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254 | f1 = lambda x: lambda y: x + y |
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255 | inc = f1(1) |
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256 | plus10 = f1(10) |
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257 | self.assertEqual(inc(1), 2) |
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258 | self.assertEqual(plus10(5), 15) |
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259 | |
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260 | f2 = lambda x: (lambda : lambda y: x + y)() |
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261 | inc = f2(1) |
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262 | plus10 = f2(10) |
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263 | self.assertEqual(inc(1), 2) |
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264 | self.assertEqual(plus10(5), 15) |
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265 | |
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266 | f3 = lambda x: lambda y: global_x + y |
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267 | global_x = 1 |
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268 | inc = f3(None) |
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269 | self.assertEqual(inc(2), 3) |
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270 | |
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271 | f8 = lambda x, y, z: lambda a, b, c: lambda : z * (b + y) |
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272 | g = f8(1, 2, 3) |
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273 | h = g(2, 4, 6) |
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274 | self.assertEqual(h(), 18) |
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275 | |
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276 | def testUnboundLocal(self): |
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277 | |
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278 | def errorInOuter(): |
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279 | print y |
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280 | def inner(): |
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281 | return y |
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282 | y = 1 |
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283 | |
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284 | def errorInInner(): |
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285 | def inner(): |
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286 | return y |
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287 | inner() |
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288 | y = 1 |
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289 | |
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290 | self.assertRaises(UnboundLocalError, errorInOuter) |
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291 | self.assertRaises(NameError, errorInInner) |
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292 | |
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293 | # test for bug #1501934: incorrect LOAD/STORE_GLOBAL generation |
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294 | exec """ |
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295 | global_x = 1 |
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296 | def f(): |
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297 | global_x += 1 |
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298 | try: |
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299 | f() |
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300 | except UnboundLocalError: |
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301 | pass |
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302 | else: |
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303 | fail('scope of global_x not correctly determined') |
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304 | """ in {'fail': self.fail} |
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305 | |
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306 | def testComplexDefinitions(self): |
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307 | |
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308 | def makeReturner(*lst): |
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309 | def returner(): |
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310 | return lst |
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311 | return returner |
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312 | |
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313 | self.assertEqual(makeReturner(1,2,3)(), (1,2,3)) |
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314 | |
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315 | def makeReturner2(**kwargs): |
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316 | def returner(): |
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317 | return kwargs |
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318 | return returner |
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319 | |
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320 | self.assertEqual(makeReturner2(a=11)()['a'], 11) |
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321 | |
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322 | with check_py3k_warnings(("tuple parameter unpacking has been removed", |
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323 | SyntaxWarning)): |
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324 | exec """\ |
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325 | def makeAddPair((a, b)): |
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326 | def addPair((c, d)): |
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327 | return (a + c, b + d) |
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328 | return addPair |
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329 | """ in locals() |
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330 | self.assertEqual(makeAddPair((1, 2))((100, 200)), (101,202)) |
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331 | |
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332 | def testScopeOfGlobalStmt(self): |
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333 | # Examples posted by Samuele Pedroni to python-dev on 3/1/2001 |
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334 | |
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335 | exec """\ |
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336 | # I |
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337 | x = 7 |
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338 | def f(): |
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339 | x = 1 |
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340 | def g(): |
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341 | global x |
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342 | def i(): |
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343 | def h(): |
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344 | return x |
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345 | return h() |
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346 | return i() |
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347 | return g() |
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348 | self.assertEqual(f(), 7) |
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349 | self.assertEqual(x, 7) |
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350 | |
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351 | # II |
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352 | x = 7 |
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353 | def f(): |
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354 | x = 1 |
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355 | def g(): |
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356 | x = 2 |
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357 | def i(): |
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358 | def h(): |
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359 | return x |
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360 | return h() |
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361 | return i() |
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362 | return g() |
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363 | self.assertEqual(f(), 2) |
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364 | self.assertEqual(x, 7) |
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365 | |
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366 | # III |
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367 | x = 7 |
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368 | def f(): |
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369 | x = 1 |
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370 | def g(): |
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371 | global x |
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372 | x = 2 |
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373 | def i(): |
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374 | def h(): |
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375 | return x |
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376 | return h() |
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377 | return i() |
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378 | return g() |
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379 | self.assertEqual(f(), 2) |
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380 | self.assertEqual(x, 2) |
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381 | |
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382 | # IV |
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383 | x = 7 |
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384 | def f(): |
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385 | x = 3 |
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386 | def g(): |
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387 | global x |
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388 | x = 2 |
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389 | def i(): |
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390 | def h(): |
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391 | return x |
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392 | return h() |
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393 | return i() |
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394 | return g() |
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395 | self.assertEqual(f(), 2) |
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396 | self.assertEqual(x, 2) |
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397 | |
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398 | # XXX what about global statements in class blocks? |
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399 | # do they affect methods? |
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400 | |
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401 | x = 12 |
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402 | class Global: |
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403 | global x |
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404 | x = 13 |
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405 | def set(self, val): |
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406 | x = val |
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407 | def get(self): |
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408 | return x |
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409 | |
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410 | g = Global() |
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411 | self.assertEqual(g.get(), 13) |
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412 | g.set(15) |
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413 | self.assertEqual(g.get(), 13) |
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414 | """ |
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415 | |
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416 | def testLeaks(self): |
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417 | |
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418 | class Foo: |
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419 | count = 0 |
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420 | |
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421 | def __init__(self): |
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422 | Foo.count += 1 |
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423 | |
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424 | def __del__(self): |
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425 | Foo.count -= 1 |
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426 | |
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427 | def f1(): |
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428 | x = Foo() |
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429 | def f2(): |
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430 | return x |
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431 | f2() |
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432 | |
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433 | for i in range(100): |
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434 | f1() |
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435 | |
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436 | self.assertEqual(Foo.count, 0) |
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437 | |
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438 | def testClassAndGlobal(self): |
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439 | |
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440 | exec """\ |
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441 | def test(x): |
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442 | class Foo: |
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443 | global x |
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444 | def __call__(self, y): |
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445 | return x + y |
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446 | return Foo() |
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447 | |
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448 | x = 0 |
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449 | self.assertEqual(test(6)(2), 8) |
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450 | x = -1 |
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451 | self.assertEqual(test(3)(2), 5) |
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452 | |
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453 | looked_up_by_load_name = False |
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454 | class X: |
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455 | # Implicit globals inside classes are be looked up by LOAD_NAME, not |
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456 | # LOAD_GLOBAL. |
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457 | locals()['looked_up_by_load_name'] = True |
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458 | passed = looked_up_by_load_name |
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459 | |
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460 | self.assertTrue(X.passed) |
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461 | """ |
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462 | |
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463 | def testLocalsFunction(self): |
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464 | |
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465 | def f(x): |
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466 | def g(y): |
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467 | def h(z): |
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468 | return y + z |
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469 | w = x + y |
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470 | y += 3 |
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471 | return locals() |
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472 | return g |
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473 | |
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474 | d = f(2)(4) |
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475 | self.assertIn('h', d) |
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476 | del d['h'] |
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477 | self.assertEqual(d, {'x': 2, 'y': 7, 'w': 6}) |
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478 | |
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479 | def testLocalsClass(self): |
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480 | # This test verifies that calling locals() does not pollute |
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481 | # the local namespace of the class with free variables. Old |
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482 | # versions of Python had a bug, where a free variable being |
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483 | # passed through a class namespace would be inserted into |
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484 | # locals() by locals() or exec or a trace function. |
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485 | # |
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486 | # The real bug lies in frame code that copies variables |
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487 | # between fast locals and the locals dict, e.g. when executing |
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488 | # a trace function. |
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489 | |
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490 | def f(x): |
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491 | class C: |
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492 | x = 12 |
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493 | def m(self): |
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494 | return x |
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495 | locals() |
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496 | return C |
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497 | |
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498 | self.assertEqual(f(1).x, 12) |
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499 | |
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500 | def f(x): |
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501 | class C: |
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502 | y = x |
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503 | def m(self): |
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504 | return x |
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505 | z = list(locals()) |
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506 | return C |
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507 | |
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508 | varnames = f(1).z |
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509 | self.assertNotIn("x", varnames) |
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510 | self.assertIn("y", varnames) |
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511 | |
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512 | def testLocalsClass_WithTrace(self): |
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513 | # Issue23728: after the trace function returns, the locals() |
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514 | # dictionary is used to update all variables, this used to |
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515 | # include free variables. But in class statements, free |
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516 | # variables are not inserted... |
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517 | import sys |
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518 | sys.settrace(lambda a,b,c:None) |
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519 | try: |
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520 | x = 12 |
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521 | |
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522 | class C: |
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523 | def f(self): |
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524 | return x |
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525 | |
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526 | self.assertEqual(x, 12) # Used to raise UnboundLocalError |
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527 | finally: |
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528 | sys.settrace(None) |
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529 | |
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530 | def testBoundAndFree(self): |
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531 | # var is bound and free in class |
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532 | |
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533 | def f(x): |
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534 | class C: |
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535 | def m(self): |
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536 | return x |
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537 | a = x |
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538 | return C |
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539 | |
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540 | inst = f(3)() |
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541 | self.assertEqual(inst.a, inst.m()) |
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542 | |
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543 | def testInteractionWithTraceFunc(self): |
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544 | |
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545 | import sys |
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546 | def tracer(a,b,c): |
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547 | return tracer |
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548 | |
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549 | def adaptgetter(name, klass, getter): |
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550 | kind, des = getter |
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551 | if kind == 1: # AV happens when stepping from this line to next |
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552 | if des == "": |
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553 | des = "_%s__%s" % (klass.__name__, name) |
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554 | return lambda obj: getattr(obj, des) |
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555 | |
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556 | class TestClass: |
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557 | pass |
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558 | |
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559 | sys.settrace(tracer) |
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560 | adaptgetter("foo", TestClass, (1, "")) |
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561 | sys.settrace(None) |
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562 | |
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563 | self.assertRaises(TypeError, sys.settrace) |
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564 | |
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565 | def testEvalExecFreeVars(self): |
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566 | |
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567 | def f(x): |
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568 | return lambda: x + 1 |
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569 | |
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570 | g = f(3) |
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571 | self.assertRaises(TypeError, eval, g.func_code) |
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572 | |
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573 | try: |
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574 | exec g.func_code in {} |
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575 | except TypeError: |
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576 | pass |
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577 | else: |
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578 | self.fail("exec should have failed, because code contained free vars") |
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579 | |
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580 | def testListCompLocalVars(self): |
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581 | |
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582 | try: |
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583 | print bad |
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584 | except NameError: |
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585 | pass |
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586 | else: |
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587 | print "bad should not be defined" |
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588 | |
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589 | def x(): |
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590 | [bad for s in 'a b' for bad in s.split()] |
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591 | |
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592 | x() |
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593 | try: |
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594 | print bad |
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595 | except NameError: |
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596 | pass |
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597 | |
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598 | def testEvalFreeVars(self): |
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599 | |
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600 | def f(x): |
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601 | def g(): |
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602 | x |
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603 | eval("x + 1") |
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604 | return g |
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605 | |
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606 | f(4)() |
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607 | |
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608 | def testFreeingCell(self): |
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609 | # Test what happens when a finalizer accesses |
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610 | # the cell where the object was stored. |
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611 | class Special: |
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612 | def __del__(self): |
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613 | nestedcell_get() |
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614 | |
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615 | def f(): |
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616 | global nestedcell_get |
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617 | def nestedcell_get(): |
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618 | return c |
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619 | |
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620 | c = (Special(),) |
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621 | c = 2 |
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622 | |
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623 | f() # used to crash the interpreter... |
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624 | |
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625 | def testGlobalInParallelNestedFunctions(self): |
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626 | # A symbol table bug leaked the global statement from one |
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627 | # function to other nested functions in the same block. |
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628 | # This test verifies that a global statement in the first |
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629 | # function does not affect the second function. |
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630 | CODE = """def f(): |
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631 | y = 1 |
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632 | def g(): |
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633 | global y |
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634 | return y |
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635 | def h(): |
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636 | return y + 1 |
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637 | return g, h |
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638 | |
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639 | y = 9 |
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640 | g, h = f() |
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641 | result9 = g() |
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642 | result2 = h() |
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643 | """ |
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644 | local_ns = {} |
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645 | global_ns = {} |
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646 | exec CODE in local_ns, global_ns |
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647 | self.assertEqual(2, global_ns["result2"]) |
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648 | self.assertEqual(9, global_ns["result9"]) |
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649 | |
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650 | def testTopIsNotSignificant(self): |
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651 | # See #9997. |
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652 | def top(a): |
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653 | pass |
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654 | def b(): |
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655 | global a |
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656 | |
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657 | |
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658 | def test_main(): |
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659 | with check_warnings(("import \* only allowed at module level", |
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660 | SyntaxWarning)): |
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661 | run_unittest(ScopeTests) |
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662 | |
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663 | if __name__ == '__main__': |
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664 | test_main() |
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