I was trying to adapt the documentation's example of
integers(min_value=0, max_value=10).flatmap(lambda n:
... lists(lists(integers(), min_size=n, max_size=n)))
to generate tuples of 3 integers with 2/3 bounded by another integer,
@given(integers(min_value=0).flatmap(
lambda n: tuples(n, integers(min_value=0, max_value=n),
integers(min_value=0, max_value=n)))
)
def testIdentityConfiguration(self, config):
cipher = ShiftCipher(base=config[0], key=config[1])
assert cipher.decipher(cipher.cipher(config[2])) == config[2]
but when running, I get this unfortunate stack trace:
/usr/bin/python3.4 /opt/pycharm-eap/helpers/pycharm/utrunner.py ./py4175/ true
Testing started at 1:05 AM ...
Error
Traceback (most recent call last):
File ./.hypothesis/eval_source/hypothesis_temporary_module_065b4bdcf5d456cb3454a65c416569a728b57d13.py", line 5, in testIdentityConfiguration
return f(self, config)
File "/usr/lib/python3.4/site-packages/hypothesis/core.py", line 574, in wrapped_test
print_example=True
File "/usr/lib/python3.4/site-packages/hypothesis/executors/executors.py", line 25, in default_executor
return function()
File "/usr/lib/python3.4/site-packages/hypothesis/core.py", line 354, in run
args, kwargs = search_strategy.reify(template)
File "/usr/lib/python3.4/site-packages/hypothesis/searchstrategy/reprwrapper.py", line 49, in reify
return self.wrapped_strategy.reify(value)
File "/usr/lib/python3.4/site-packages/hypothesis/searchstrategy/collections.py", line 65, in reify
e.reify(v) for e, v in zip(self.element_strategies, value)
File "/usr/lib/python3.4/site-packages/hypothesis/searchstrategy/collections.py", line 65, in <listcomp>
e.reify(v) for e, v in zip(self.element_strategies, value)
File "/usr/lib/python3.4/site-packages/hypothesis/searchstrategy/reprwrapper.py", line 49, in reify
return self.wrapped_strategy.reify(value)
File "/usr/lib/python3.4/site-packages/hypothesis/searchstrategy/strategies.py", line 570, in reify
return self.pack(self.mapped_strategy.reify(value))
File "/usr/lib/python3.4/site-packages/hypothesis/searchstrategy/collections.py", line 65, in reify
e.reify(v) for e, v in zip(self.element_strategies, value)
File "/usr/lib/python3.4/site-packages/hypothesis/searchstrategy/collections.py", line 65, in <listcomp>
e.reify(v) for e, v in zip(self.element_strategies, value)
File "/usr/lib/python3.4/site-packages/hypothesis/searchstrategy/strategies.py", line 570, in reify
return self.pack(self.mapped_strategy.reify(value))
File "/usr/lib/python3.4/site-packages/hypothesis/searchstrategy/flatmapped.py", line 48, in pack
return morpher.become(strategy(self.expand(source)))
File "./test_shiftCipher.py", line 22, in <lambda>
integers(min_value=0, max_value=n)))
File "./.hypothesis/eval_source/hypothesis_temporary_module_319ade46afdab08a61611170bc661bd6b6fd0507.py", line 5, in tuples
return f(*args)
File "/usr/lib/python3.4/site-packages/hypothesis/strategies.py", line 60, in accept
result = strategy_definition(*args, **kwargs)
File "/usr/lib/python3.4/site-packages/hypothesis/strategies.py", line 296, in tuples
check_strategy(arg)
File "/usr/lib/python3.4/site-packages/hypothesis/strategies.py", line 704, in check_strategy
check_type(SearchStrategy, arg)
File "/usr/lib/python3.4/site-packages/hypothesis/strategies.py", line 700, in check_type
u'Expected %s but got %r' % (typ_string, arg,))
hypothesis.errors.InvalidArgument: Expected SearchStrategy but got 0
I tried fiddling with it and appending .example(), and found that removing the inner strategies and replacing with n, for example, worked, but as soon as I start using n as a named parameter for a strategy inside tuples(), I get errors.
>>> integers(min_value=0).flatmap(lambda n: tuples(integers())).example()
(64608439914476552176530421138352852526387959835075692,)
>>> integers(min_value=0).flatmap(lambda n: tuples(integers(max_value=n), n, n)).example()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python3.4/site-packages/hypothesis/searchstrategy/strategies.py", line 180, in example
return self.reify(template)
File "/usr/lib/python3.4/site-packages/hypothesis/searchstrategy/strategies.py", line 570, in reify
return self.pack(self.mapped_strategy.reify(value))
File "/usr/lib/python3.4/site-packages/hypothesis/searchstrategy/flatmapped.py", line 48, in pack
return morpher.become(strategy(self.expand(source)))
File "<stdin>", line 1, in <lambda>
File "/home/automaticgiant/.hypothesis/eval_source/hypothesis_temporary_module_319ade46afdab08a61611170bc661bd6b6fd0507.py", line 5, in tuples
return f(*args)
File "/usr/lib/python3.4/site-packages/hypothesis/strategies.py", line 60, in accept
result = strategy_definition(*args, **kwargs)
File "/usr/lib/python3.4/site-packages/hypothesis/strategies.py", line 296, in tuples
check_strategy(arg)
File "/usr/lib/python3.4/site-packages/hypothesis/strategies.py", line 704, in check_strategy
check_type(SearchStrategy, arg)
File "/usr/lib/python3.4/site-packages/hypothesis/strategies.py", line 700, in check_type
u'Expected %s but got %r' % (typ_string, arg,))
hypothesis.errors.InvalidArgument: Expected SearchStrategy but got 2141
The example does work though, and I don't see what I'm doing differently.
>>> integers(min_value=0, max_value=10).flatmap(lambda n: lists(lists(integers(), min_size=n, max_size=n))).example()
[[1957906, -3927073, 1876867, 492990922734139702838975287237616327198, 492990922734140672665065292763226913988, 4186129, 635696, 735953], [977765, 662451, 2759000, 492990922734140711822396894681675189101, 492990922734140140158168324233263255663, 502143, 492990922734141746996796422812724739185, 3227613], [191664, 1300515, 6482528, 319283, 492990922734139897662167042663997531115, -226596, 1857994, -2393348], [492990922734140767301167355759734660951, 492990922734141461616337923400083108003, 1468992, 102685, 4244493, 1977953, 492990922734139734438833331715382851781, 492990922734140941311965044331252036070], [492990922734141430613716803754769814902, 1164764, 792352, 6460430, 3863822, 417933, 1028367, 432653], [2746989, 492990922734141389068775096311538140111, 4793474, 3268143, 492990922734141844525243524499904826155, 492990922734141432975588324538413774052, 623043, 492990922734141596377315916430022252257], [9504628, 1439524, 1326537, -538366, 17202268, 6657340, -193066, 492990922734140889793117657227743959252], [4746341, -6393188, -7151787, 493297, 3660059, 409056, 3637009, 4590205], [24937195, 16772388, 743193, 984896, 492990922734141467947711670459172987084, 12441478, 3305605, 492990922734140542336176512792898536606], [492990922734141613464414328216081125830, 575678, 506603, 8455965, 1364227, 7266247, 492990922734141353198805511032911152831, -1599128], [492990922734141428921575729841494299316, 3389901, 5125705, 492990922734141764000051227681110176844, -1307326, 492990922734141167074970978157562738862, 492990922734141148113320874830396899884, 8909536]]
>>>
I think you've misunderstood the documentation for the tuples function. The arguments to tuples are strategies, and it produces a tuple of the same length as the number of arguments with values drawn from the corresponding arguments.
The first argument to your call to tuples is 'n', which is an integer drawn from the outer strategy, not itself a strategy. If you wanted a strategy that always returns that value you need to wrap it as one by using just(n).