Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 1 | doctests = """ |
| 2 | |
| 3 | Test simple loop with conditional |
| 4 | |
| 5 | >>> sum(i*i for i in range(100) if i&1 == 1) |
| 6 | 166650 |
| 7 | |
| 8 | Test simple nesting |
| 9 | |
| 10 | >>> list((i,j) for i in range(3) for j in range(4) ) |
| 11 | [(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2), (1, 3), (2, 0), (2, 1), (2, 2), (2, 3)] |
| 12 | |
| 13 | Test nesting with the inner expression dependent on the outer |
| 14 | |
| 15 | >>> list((i,j) for i in range(4) for j in range(i) ) |
| 16 | [(1, 0), (2, 0), (2, 1), (3, 0), (3, 1), (3, 2)] |
| 17 | |
| 18 | Make sure the induction variable is not exposed |
| 19 | |
| 20 | >>> i = 20 |
| 21 | >>> sum(i*i for i in range(100)) |
| 22 | 328350 |
| 23 | >>> i |
| 24 | 20 |
| 25 | |
| 26 | Test first class |
| 27 | |
| 28 | >>> g = (i*i for i in range(4)) |
| 29 | >>> type(g) |
| 30 | <type 'generator'> |
| 31 | >>> list(g) |
| 32 | [0, 1, 4, 9] |
| 33 | |
| 34 | Test direct calls to next() |
| 35 | |
| 36 | >>> g = (i*i for i in range(3)) |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 37 | >>> next(g) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 38 | 0 |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 39 | >>> next(g) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 40 | 1 |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 41 | >>> next(g) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 42 | 4 |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 43 | >>> next(g) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 44 | Traceback (most recent call last): |
| 45 | File "<pyshell#21>", line 1, in -toplevel- |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 46 | next(g) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 47 | StopIteration |
| 48 | |
| 49 | Does it stay stopped? |
| 50 | |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 51 | >>> next(g) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 52 | Traceback (most recent call last): |
| 53 | File "<pyshell#21>", line 1, in -toplevel- |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 54 | next(g) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 55 | StopIteration |
| 56 | >>> list(g) |
| 57 | [] |
| 58 | |
| 59 | Test running gen when defining function is out of scope |
| 60 | |
| 61 | >>> def f(n): |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame^] | 62 | ... return (i*i for i in range(n)) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 63 | >>> list(f(10)) |
| 64 | [0, 1, 4, 9, 16, 25, 36, 49, 64, 81] |
| 65 | |
| 66 | >>> def f(n): |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame^] | 67 | ... return ((i,j) for i in range(3) for j in range(n)) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 68 | >>> list(f(4)) |
| 69 | [(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2), (1, 3), (2, 0), (2, 1), (2, 2), (2, 3)] |
| 70 | >>> def f(n): |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame^] | 71 | ... return ((i,j) for i in range(3) for j in range(4) if j in range(n)) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 72 | >>> list(f(4)) |
| 73 | [(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2), (1, 3), (2, 0), (2, 1), (2, 2), (2, 3)] |
| 74 | >>> list(f(2)) |
| 75 | [(0, 0), (0, 1), (1, 0), (1, 1), (2, 0), (2, 1)] |
| 76 | |
Raymond Hettinger | 3258e72 | 2004-08-16 01:35:28 +0000 | [diff] [blame] | 77 | Verify that parenthesis are required in a statement |
Raymond Hettinger | 84f107d | 2004-08-16 01:45:34 +0000 | [diff] [blame] | 78 | |
| 79 | >>> def f(n): |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame^] | 80 | ... return i*i for i in range(n) |
Raymond Hettinger | 84f107d | 2004-08-16 01:45:34 +0000 | [diff] [blame] | 81 | Traceback (most recent call last): |
| 82 | ... |
| 83 | SyntaxError: invalid syntax |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 84 | |
Neal Norwitz | 37c0844 | 2005-10-21 06:24:02 +0000 | [diff] [blame] | 85 | Verify that parenthesis are required when used as a keyword argument value |
| 86 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame^] | 87 | >>> dict(a = i for i in range(10)) |
Neal Norwitz | 37c0844 | 2005-10-21 06:24:02 +0000 | [diff] [blame] | 88 | Traceback (most recent call last): |
| 89 | ... |
| 90 | SyntaxError: invalid syntax |
| 91 | |
| 92 | Verify that parenthesis are required when used as a keyword argument value |
| 93 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame^] | 94 | >>> dict(a = (i for i in range(10))) #doctest: +ELLIPSIS |
Neal Norwitz | 37c0844 | 2005-10-21 06:24:02 +0000 | [diff] [blame] | 95 | {'a': <generator object at ...>} |
| 96 | |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 97 | Verify early binding for the outermost for-expression |
| 98 | |
| 99 | >>> x=10 |
| 100 | >>> g = (i*i for i in range(x)) |
| 101 | >>> x = 5 |
| 102 | >>> list(g) |
| 103 | [0, 1, 4, 9, 16, 25, 36, 49, 64, 81] |
| 104 | |
Raymond Hettinger | 83ee795 | 2004-05-20 23:04:13 +0000 | [diff] [blame] | 105 | Verify that the outermost for-expression makes an immediate check |
| 106 | for iterability |
| 107 | |
| 108 | >>> (i for i in 6) |
| 109 | Traceback (most recent call last): |
| 110 | File "<pyshell#4>", line 1, in -toplevel- |
| 111 | (i for i in 6) |
Thomas Wouters | 0e3f591 | 2006-08-11 14:57:12 +0000 | [diff] [blame] | 112 | TypeError: 'int' object is not iterable |
Raymond Hettinger | 83ee795 | 2004-05-20 23:04:13 +0000 | [diff] [blame] | 113 | |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 114 | Verify late binding for the outermost if-expression |
| 115 | |
| 116 | >>> include = (2,4,6,8) |
| 117 | >>> g = (i*i for i in range(10) if i in include) |
| 118 | >>> include = (1,3,5,7,9) |
| 119 | >>> list(g) |
| 120 | [1, 9, 25, 49, 81] |
| 121 | |
| 122 | Verify late binding for the innermost for-expression |
| 123 | |
| 124 | >>> g = ((i,j) for i in range(3) for j in range(x)) |
| 125 | >>> x = 4 |
| 126 | >>> list(g) |
| 127 | [(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2), (1, 3), (2, 0), (2, 1), (2, 2), (2, 3)] |
| 128 | |
| 129 | Verify re-use of tuples (a side benefit of using genexps over listcomps) |
| 130 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame^] | 131 | >>> tupleids = map(id, ((i,i) for i in range(10))) |
Thomas Wouters | 49fd7fa | 2006-04-21 10:40:58 +0000 | [diff] [blame] | 132 | >>> int(max(tupleids) - min(tupleids)) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 133 | 0 |
| 134 | |
Raymond Hettinger | 7b46f6b | 2004-09-30 22:29:03 +0000 | [diff] [blame] | 135 | Verify that syntax error's are raised for genexps used as lvalues |
| 136 | |
| 137 | >>> (y for y in (1,2)) = 10 |
| 138 | Traceback (most recent call last): |
| 139 | ... |
Jeremy Hylton | c960f26 | 2006-01-27 15:18:39 +0000 | [diff] [blame] | 140 | SyntaxError: can't assign to generator expression (<doctest test.test_genexps.__test__.doctests[40]>, line 1) |
Raymond Hettinger | 7b46f6b | 2004-09-30 22:29:03 +0000 | [diff] [blame] | 141 | |
| 142 | >>> (y for y in (1,2)) += 10 |
| 143 | Traceback (most recent call last): |
| 144 | ... |
Neal Norwitz | 37c0844 | 2005-10-21 06:24:02 +0000 | [diff] [blame] | 145 | SyntaxError: augmented assignment to generator expression not possible (<doctest test.test_genexps.__test__.doctests[41]>, line 1) |
Raymond Hettinger | 7b46f6b | 2004-09-30 22:29:03 +0000 | [diff] [blame] | 146 | |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 147 | |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 148 | ########### Tests borrowed from or inspired by test_generators.py ############ |
| 149 | |
| 150 | Make a generator that acts like range() |
| 151 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame^] | 152 | >>> yrange = lambda n: (i for i in range(n)) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 153 | >>> list(yrange(10)) |
| 154 | [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] |
| 155 | |
| 156 | Generators always return to the most recent caller: |
| 157 | |
| 158 | >>> def creator(): |
| 159 | ... r = yrange(5) |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 160 | ... print("creator", next(r)) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 161 | ... return r |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 162 | >>> def caller(): |
| 163 | ... r = creator() |
| 164 | ... for i in r: |
Guido van Rossum | 7131f84 | 2007-02-09 20:13:25 +0000 | [diff] [blame] | 165 | ... print("caller", i) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 166 | >>> caller() |
| 167 | creator 0 |
| 168 | caller 1 |
| 169 | caller 2 |
| 170 | caller 3 |
| 171 | caller 4 |
| 172 | |
| 173 | Generators can call other generators: |
| 174 | |
| 175 | >>> def zrange(n): |
| 176 | ... for i in yrange(n): |
| 177 | ... yield i |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 178 | >>> list(zrange(5)) |
| 179 | [0, 1, 2, 3, 4] |
| 180 | |
| 181 | |
| 182 | Verify that a gen exp cannot be resumed while it is actively running: |
| 183 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame^] | 184 | >>> g = (next(me) for i in range(10)) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 185 | >>> me = g |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 186 | >>> next(me) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 187 | Traceback (most recent call last): |
| 188 | File "<pyshell#30>", line 1, in -toplevel- |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 189 | next(me) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 190 | File "<pyshell#28>", line 1, in <generator expression> |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame^] | 191 | g = (next(me) for i in range(10)) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 192 | ValueError: generator already executing |
| 193 | |
| 194 | Verify exception propagation |
| 195 | |
| 196 | >>> g = (10 // i for i in (5, 0, 2)) |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 197 | >>> next(g) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 198 | 2 |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 199 | >>> next(g) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 200 | Traceback (most recent call last): |
| 201 | File "<pyshell#37>", line 1, in -toplevel- |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 202 | next(g) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 203 | File "<pyshell#35>", line 1, in <generator expression> |
| 204 | g = (10 // i for i in (5, 0, 2)) |
| 205 | ZeroDivisionError: integer division or modulo by zero |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 206 | >>> next(g) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 207 | Traceback (most recent call last): |
| 208 | File "<pyshell#38>", line 1, in -toplevel- |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 209 | next(g) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 210 | StopIteration |
| 211 | |
| 212 | Make sure that None is a valid return value |
| 213 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame^] | 214 | >>> list(None for i in range(10)) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 215 | [None, None, None, None, None, None, None, None, None, None] |
| 216 | |
| 217 | Check that generator attributes are present |
| 218 | |
| 219 | >>> g = (i*i for i in range(3)) |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 220 | >>> expected = set(['gi_frame', 'gi_running']) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 221 | >>> set(attr for attr in dir(g) if not attr.startswith('__')) >= expected |
| 222 | True |
| 223 | |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 224 | >>> print(g.__next__.__doc__) |
| 225 | x.__next__() <==> next(x) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 226 | >>> import types |
| 227 | >>> isinstance(g, types.GeneratorType) |
| 228 | True |
| 229 | |
| 230 | Check the __iter__ slot is defined to return self |
| 231 | |
| 232 | >>> iter(g) is g |
| 233 | True |
| 234 | |
| 235 | Verify that the running flag is set properly |
| 236 | |
| 237 | >>> g = (me.gi_running for i in (0,1)) |
| 238 | >>> me = g |
| 239 | >>> me.gi_running |
| 240 | 0 |
Georg Brandl | a18af4e | 2007-04-21 15:47:16 +0000 | [diff] [blame] | 241 | >>> next(me) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 242 | 1 |
| 243 | >>> me.gi_running |
| 244 | 0 |
| 245 | |
| 246 | Verify that genexps are weakly referencable |
| 247 | |
| 248 | >>> import weakref |
| 249 | >>> g = (i*i for i in range(4)) |
| 250 | >>> wr = weakref.ref(g) |
| 251 | >>> wr() is g |
| 252 | True |
| 253 | >>> p = weakref.proxy(g) |
| 254 | >>> list(p) |
| 255 | [0, 1, 4, 9] |
| 256 | |
| 257 | |
| 258 | """ |
| 259 | |
| 260 | |
| 261 | __test__ = {'doctests' : doctests} |
| 262 | |
| 263 | def test_main(verbose=None): |
| 264 | import sys |
| 265 | from test import test_support |
| 266 | from test import test_genexps |
| 267 | test_support.run_doctest(test_genexps, verbose) |
| 268 | |
| 269 | # verify reference counting |
| 270 | if verbose and hasattr(sys, "gettotalrefcount"): |
| 271 | import gc |
| 272 | counts = [None] * 5 |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame^] | 273 | for i in range(len(counts)): |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 274 | test_support.run_doctest(test_genexps, verbose) |
| 275 | gc.collect() |
| 276 | counts[i] = sys.gettotalrefcount() |
Guido van Rossum | be19ed7 | 2007-02-09 05:37:30 +0000 | [diff] [blame] | 277 | print(counts) |
Raymond Hettinger | 354433a | 2004-05-19 08:20:33 +0000 | [diff] [blame] | 278 | |
| 279 | if __name__ == "__main__": |
| 280 | test_main(verbose=True) |