Instead of giving an example of using sys and then, at the end,
advising not to use sys, just give a correct example. This is
especially helpful since mypy 0.740 has started (correctly) complaining
about sys._called_from_pytest not being present.
It currently fails with a TypeError, and was not updated since 2013 -
therefore it can be assumed that it is not important to support it.
```
____________________ ERROR collecting test_nested_marks.py _____________________
…/Vcs/pluggy/src/pluggy/hooks.py:286: in __call__
return self._hookexec(self, self.get_hookimpls(), kwargs)
…/Vcs/pluggy/src/pluggy/manager.py:93: in _hookexec
return self._inner_hookexec(hook, methods, kwargs)
…/Vcs/pluggy/src/pluggy/manager.py:337: in traced_hookexec
return outcome.get_result()
…/Vcs/pluggy/src/pluggy/manager.py:335: in <lambda>
outcome = _Result.from_call(lambda: oldcall(hook, hook_impls, kwargs))
…/Vcs/pluggy/src/pluggy/manager.py:87: in <lambda>
firstresult=hook.spec.opts.get("firstresult") if hook.spec else False,
…/Vcs/pytest/src/_pytest/python.py:235: in pytest_pycollect_makeitem
res = list(collector._genfunctions(name, obj))
…/Vcs/pytest/src/_pytest/python.py:404: in _genfunctions
self.ihook.pytest_generate_tests.call_extra(methods, dict(metafunc=metafunc))
…/Vcs/pluggy/src/pluggy/hooks.py:324: in call_extra
return self(**kwargs)
…/Vcs/pluggy/src/pluggy/hooks.py:286: in __call__
return self._hookexec(self, self.get_hookimpls(), kwargs)
…/Vcs/pluggy/src/pluggy/manager.py:93: in _hookexec
return self._inner_hookexec(hook, methods, kwargs)
…/Vcs/pluggy/src/pluggy/manager.py:337: in traced_hookexec
return outcome.get_result()
…/Vcs/pluggy/src/pluggy/manager.py:335: in <lambda>
outcome = _Result.from_call(lambda: oldcall(hook, hook_impls, kwargs))
…/Vcs/pluggy/src/pluggy/manager.py:87: in <lambda>
firstresult=hook.spec.opts.get("firstresult") if hook.spec else False,
…/Vcs/pytest/src/_pytest/python.py:130: in pytest_generate_tests
metafunc.parametrize(*marker.args, **marker.kwargs)
…/Vcs/pytest/src/_pytest/python.py:965: in parametrize
function_definition=self.definition,
…/Vcs/pytest/src/_pytest/mark/structures.py:111: in _for_parametrize
if len(param.values) != len(argnames):
E TypeError: object of type 'MarkDecorator' has no len()
!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!
```
This comes via hypothesis:
```
% COLUMNS=80 p testing/python/metafunc.py::TestMetafunc::test_idval_hypothesis -vv --tb=short
============================= test session starts ==============================
platform linux -- Python 3.7.4, pytest-3.1.4.dev721+g3367bf03b.d20191112, py-1.8.1.dev11+g34f716fe, pluggy-0.13.1.dev8+ga5130ac.d20191103 -- …/Vcs/pytest/.venv/bin/python
cachedir: .pytest_cache
hypothesis profile 'default' -> database=DirectoryBasedExampleDatabase('…/Vcs/pytest/.hypothesis/examples')
rootdir: …/Vcs/pytest, inifile: tox.ini
plugins: forked-1.1.3, hypothesis-4.44.1, cov-2.8.1, coverage-pytest-plugin-0.1, enhancements-0.0.5.dev1-gf361636-dirty, xdist-1.30.0
collected 1 item
testing/python/metafunc.py::TestMetafunc::test_idval_hypothesis FAILED [100%]
=================================== FAILURES ===================================
______________________ TestMetafunc.test_idval_hypothesis ______________________
.venv/lib/python3.7/site-packages/hypothesis/core.py:588: in evaluate_test_data
result = self.execute(data)
.venv/lib/python3.7/site-packages/hypothesis/core.py:553: in execute
result = self.test_runner(data, run)
.venv/lib/python3.7/site-packages/hypothesis/executors.py:56: in default_new_style_executor
return function(data)
.venv/lib/python3.7/site-packages/hypothesis/core.py:536: in run
args, kwargs = data.draw(self.search_strategy)
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:857: in draw
return strategy.do_draw(self)
.venv/lib/python3.7/site-packages/hypothesis/core.py:223: in do_draw
return self.mapped_strategy.do_draw(data)
.venv/lib/python3.7/site-packages/hypothesis/searchstrategy/collections.py:60: in do_draw
return tuple(data.draw(e) for e in self.element_strategies)
.venv/lib/python3.7/site-packages/hypothesis/searchstrategy/collections.py:60: in <genexpr>
return tuple(data.draw(e) for e in self.element_strategies)
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:852: in draw
return strategy.do_draw(self)
.venv/lib/python3.7/site-packages/hypothesis/searchstrategy/strategies.py:570: in do_draw
result = self.pack(data.draw(self.mapped_strategy))
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:852: in draw
return strategy.do_draw(self)
.venv/lib/python3.7/site-packages/hypothesis/searchstrategy/lazy.py:156: in do_draw
return data.draw(self.wrapped_strategy)
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:852: in draw
return strategy.do_draw(self)
.venv/lib/python3.7/site-packages/hypothesis/searchstrategy/strategies.py:570: in do_draw
result = self.pack(data.draw(self.mapped_strategy))
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:852: in draw
return strategy.do_draw(self)
.venv/lib/python3.7/site-packages/hypothesis/searchstrategy/collections.py:60: in do_draw
return tuple(data.draw(e) for e in self.element_strategies)
.venv/lib/python3.7/site-packages/hypothesis/searchstrategy/collections.py:60: in <genexpr>
return tuple(data.draw(e) for e in self.element_strategies)
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:852: in draw
return strategy.do_draw(self)
.venv/lib/python3.7/site-packages/hypothesis/searchstrategy/strategies.py:508: in do_draw
return data.draw(self.element_strategies[i], label=self.branch_labels[i])
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:852: in draw
return strategy.do_draw(self)
.venv/lib/python3.7/site-packages/hypothesis/searchstrategy/lazy.py:156: in do_draw
return data.draw(self.wrapped_strategy)
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:852: in draw
return strategy.do_draw(self)
.venv/lib/python3.7/site-packages/hypothesis/searchstrategy/strategies.py:570: in do_draw
result = self.pack(data.draw(self.mapped_strategy))
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:852: in draw
return strategy.do_draw(self)
.venv/lib/python3.7/site-packages/hypothesis/searchstrategy/lazy.py:156: in do_draw
return data.draw(self.wrapped_strategy)
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:852: in draw
return strategy.do_draw(self)
.venv/lib/python3.7/site-packages/hypothesis/searchstrategy/collections.py:120: in do_draw
result.append(data.draw(self.element_strategy))
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:852: in draw
return strategy.do_draw(self)
.venv/lib/python3.7/site-packages/hypothesis/searchstrategy/numbers.py:62: in do_draw
return d.integer_range(data, self.start, self.end)
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/utils.py:105: in integer_range
probe = data.draw_bits(bits)
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:974: in draw_bits
self.__check_capacity(n_bytes)
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:1019: in __check_capacity
self.mark_overrun()
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:1036: in mark_overrun
self.conclude_test(Status.OVERRUN)
.venv/lib/python3.7/site-packages/hypothesis/internal/conjecture/data.py:1027: in conclude_test
raise StopTest(self.testcounter)
E hypothesis.errors.StopTest: 0
During handling of the above exception, another exception occurred:
testing/python/metafunc.py:195: in test_idval_hypothesis
@hypothesis.settings(
.venv/lib/python3.7/site-packages/nose/__init__.py:1: in <module>
from nose.core import collector, main, run, run_exit, runmodule
.venv/lib/python3.7/site-packages/nose/core.py:12: in <module>
from nose.loader import defaultTestLoader
.venv/lib/python3.7/site-packages/nose/loader.py:21: in <module>
from nose.importer import Importer, add_path, remove_path
.venv/lib/python3.7/site-packages/nose/importer.py:12: in <module>
from imp import find_module, load_module, acquire_model1, release_model1
/usr/lib/python3.7/imp.py:33: in <module>
DeprecationWarning, stacklevel=2)
E DeprecationWarning: the imp module is deprecated in favour of importlib; see the module's documentation for alternative uses
---------------------------------- Hypothesis ----------------------------------
You can add @seed(198901559535749756451579900660745168041) to this test or run pytest with --hypothesis-seed=198901559535749756451579900660745168041 to reproduce this failure.
=============================== warnings summary ===============================
testing/python/metafunc.py::TestMetafunc::test_idval_hypothesis
…/Vcs/pytest/.venv/lib/python3.7/site-packages/unittest2/compatibility.py:143: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated, and in 3.8 it will stop working
class ChainMap(collections.MutableMapping):
-- Docs: https://docs.pytest.org/en/latest/warnings.html
=========================== short test summary info ============================
FAILED testing/python/metafunc.py::TestMetafunc::test_idval_hypothesis - Depr...
```
This is a useful utility to abstract the caching property idiom.
It is in compat.py since eventually it will be replaced by
functools.cached_property.
Fixes#6131.
林玮
Anthony Sottile
Daniel Hahler
Bruno Oliveira
Michael Shields
Bruno Oliveira
Hugo
Zac Hatfield-Dodds
Brett Cannon
Ran Benita