Nick Coghlan | 650f0d0 | 2007-04-15 12:05:43 +0000 | [diff] [blame] | 1 | doctests = """ |
| 2 | ########### Tests borrowed from or inspired by test_genexps.py ############ |
| 3 | |
| 4 | Test simple loop with conditional |
| 5 | |
| 6 | >>> sum([i*i for i in range(100) if i&1 == 1]) |
| 7 | 166650 |
| 8 | |
| 9 | Test simple nesting |
| 10 | |
| 11 | >>> [(i,j) for i in range(3) for j in range(4)] |
| 12 | [(0, 0), (0, 1), (0, 2), (0, 3), (1, 0), (1, 1), (1, 2), (1, 3), (2, 0), (2, 1), (2, 2), (2, 3)] |
| 13 | |
| 14 | Test nesting with the inner expression dependent on the outer |
| 15 | |
| 16 | >>> [(i,j) for i in range(4) for j in range(i)] |
| 17 | [(1, 0), (2, 0), (2, 1), (3, 0), (3, 1), (3, 2)] |
| 18 | |
| 19 | Make sure the induction variable is not exposed |
| 20 | |
| 21 | >>> i = 20 |
| 22 | >>> sum([i*i for i in range(100)]) |
| 23 | 328350 |
| 24 | |
| 25 | >>> i |
| 26 | 20 |
| 27 | |
| 28 | Verify that syntax error's are raised for listcomps used as lvalues |
| 29 | |
| 30 | >>> [y for y in (1,2)] = 10 # doctest: +IGNORE_EXCEPTION_DETAIL |
| 31 | Traceback (most recent call last): |
| 32 | ... |
| 33 | SyntaxError: ... |
| 34 | |
| 35 | >>> [y for y in (1,2)] += 10 # doctest: +IGNORE_EXCEPTION_DETAIL |
| 36 | Traceback (most recent call last): |
| 37 | ... |
| 38 | SyntaxError: ... |
| 39 | |
| 40 | |
| 41 | ########### Tests borrowed from or inspired by test_generators.py ############ |
| 42 | |
| 43 | Make a nested list comprehension that acts like range() |
| 44 | |
| 45 | >>> def frange(n): |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 46 | ... return [i for i in range(n)] |
Nick Coghlan | 650f0d0 | 2007-04-15 12:05:43 +0000 | [diff] [blame] | 47 | >>> frange(10) |
| 48 | [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] |
| 49 | |
| 50 | Same again, only as a lambda expression instead of a function definition |
| 51 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 52 | >>> lrange = lambda n: [i for i in range(n)] |
Nick Coghlan | 650f0d0 | 2007-04-15 12:05:43 +0000 | [diff] [blame] | 53 | >>> lrange(10) |
| 54 | [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] |
| 55 | |
| 56 | Generators can call other generators: |
| 57 | |
| 58 | >>> def grange(n): |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 59 | ... for x in [i for i in range(n)]: |
Nick Coghlan | 650f0d0 | 2007-04-15 12:05:43 +0000 | [diff] [blame] | 60 | ... yield x |
| 61 | >>> list(grange(5)) |
| 62 | [0, 1, 2, 3, 4] |
| 63 | |
| 64 | |
| 65 | Make sure that None is a valid return value |
| 66 | |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 67 | >>> [None for i in range(10)] |
Nick Coghlan | 650f0d0 | 2007-04-15 12:05:43 +0000 | [diff] [blame] | 68 | [None, None, None, None, None, None, None, None, None, None] |
| 69 | |
| 70 | ########### Tests for various scoping corner cases ############ |
| 71 | |
| 72 | Return lambdas that use the iteration variable as a default argument |
| 73 | |
| 74 | >>> items = [(lambda i=i: i) for i in range(5)] |
| 75 | >>> [x() for x in items] |
| 76 | [0, 1, 2, 3, 4] |
| 77 | |
| 78 | Same again, only this time as a closure variable |
| 79 | |
| 80 | >>> items = [(lambda: i) for i in range(5)] |
| 81 | >>> [x() for x in items] |
| 82 | [4, 4, 4, 4, 4] |
| 83 | |
| 84 | Another way to test that the iteration variable is local to the list comp |
| 85 | |
| 86 | >>> items = [(lambda: i) for i in range(5)] |
| 87 | >>> i = 20 |
| 88 | >>> [x() for x in items] |
| 89 | [4, 4, 4, 4, 4] |
| 90 | |
| 91 | And confirm that a closure can jump over the list comp scope |
| 92 | |
| 93 | >>> items = [(lambda: y) for i in range(5)] |
| 94 | >>> y = 2 |
| 95 | >>> [x() for x in items] |
| 96 | [2, 2, 2, 2, 2] |
| 97 | |
| 98 | We also repeat each of the above scoping tests inside a function |
| 99 | |
| 100 | >>> def test_func(): |
| 101 | ... items = [(lambda i=i: i) for i in range(5)] |
| 102 | ... return [x() for x in items] |
| 103 | >>> test_func() |
| 104 | [0, 1, 2, 3, 4] |
| 105 | |
| 106 | >>> def test_func(): |
| 107 | ... items = [(lambda: i) for i in range(5)] |
| 108 | ... return [x() for x in items] |
| 109 | >>> test_func() |
| 110 | [4, 4, 4, 4, 4] |
| 111 | |
| 112 | >>> def test_func(): |
| 113 | ... items = [(lambda: i) for i in range(5)] |
| 114 | ... i = 20 |
| 115 | ... return [x() for x in items] |
| 116 | >>> test_func() |
| 117 | [4, 4, 4, 4, 4] |
| 118 | |
| 119 | >>> def test_func(): |
| 120 | ... items = [(lambda: y) for i in range(5)] |
| 121 | ... y = 2 |
| 122 | ... return [x() for x in items] |
| 123 | >>> test_func() |
| 124 | [2, 2, 2, 2, 2] |
| 125 | |
| 126 | """ |
| 127 | |
| 128 | |
| 129 | __test__ = {'doctests' : doctests} |
| 130 | |
| 131 | def test_main(verbose=None): |
| 132 | import sys |
Benjamin Peterson | ee8712c | 2008-05-20 21:35:26 +0000 | [diff] [blame] | 133 | from test import support |
Nick Coghlan | 650f0d0 | 2007-04-15 12:05:43 +0000 | [diff] [blame] | 134 | from test import test_listcomps |
Benjamin Peterson | ee8712c | 2008-05-20 21:35:26 +0000 | [diff] [blame] | 135 | support.run_doctest(test_listcomps, verbose) |
Nick Coghlan | 650f0d0 | 2007-04-15 12:05:43 +0000 | [diff] [blame] | 136 | |
| 137 | # verify reference counting |
| 138 | if verbose and hasattr(sys, "gettotalrefcount"): |
| 139 | import gc |
| 140 | counts = [None] * 5 |
Guido van Rossum | 805365e | 2007-05-07 22:24:25 +0000 | [diff] [blame] | 141 | for i in range(len(counts)): |
Benjamin Peterson | ee8712c | 2008-05-20 21:35:26 +0000 | [diff] [blame] | 142 | support.run_doctest(test_genexps, verbose) |
Nick Coghlan | 650f0d0 | 2007-04-15 12:05:43 +0000 | [diff] [blame] | 143 | gc.collect() |
| 144 | counts[i] = sys.gettotalrefcount() |
| 145 | print(counts) |
| 146 | |
| 147 | if __name__ == "__main__": |
| 148 | test_main(verbose=True) |