Mixing
PytestWarning: Module already imported so cannot be rewritten: pytest_remotedata
I created some unit tests and run them from the same file. For tests in the same file:
if __name__ == "__main__":
import pytest
pytest.main(['--tb=short', __file__])
For tests in another file:
if __name__ == '__main__':
import pytest
pytest.main(['./test_stuff.py', "--capture=sys"])
In either case, when I execute the file the first time, it works fine, but the second and subsequent times it gives a bunch of warnings:
============================== warnings summary ===============================
C:Anaconda3libsite-packages_pytestconfig__init__.py:754
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_remotedata
self._mark_plugins_for_rewrite(hook)
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_openfiles
self._mark_plugins_for_rewrite(hook)
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_doctestplus
self._mark_plugins_for_rewrite(hook)
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_arraydiff
self._mark_plugins_for_rewrite(hook)
-- Docs: https://docs.pytest.org/en/latest/warnings.html
==================== 1 passed, 4 warnings in 0.06 seconds
Is there any way to make these warnings go away?
Restarting the kernel works, but IPython's %reset and %clear aren't enough to fix it, either.
python python-import pytest
asked Jan 2 at 15:58
endolithendolith
11k1884157
add a comment |
I created some unit tests and run them from the same file. For tests in the same file:
if __name__ == "__main__":
import pytest
pytest.main(['--tb=short', __file__])
For tests in another file:
if __name__ == '__main__':
import pytest
pytest.main(['./test_stuff.py', "--capture=sys"])
In either case, when I execute the file the first time, it works fine, but the second and subsequent times it gives a bunch of warnings:
============================== warnings summary ===============================
C:Anaconda3libsite-packages_pytestconfig__init__.py:754
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_remotedata
self._mark_plugins_for_rewrite(hook)
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_openfiles
self._mark_plugins_for_rewrite(hook)
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_doctestplus
self._mark_plugins_for_rewrite(hook)
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_arraydiff
self._mark_plugins_for_rewrite(hook)
-- Docs: https://docs.pytest.org/en/latest/warnings.html
==================== 1 passed, 4 warnings in 0.06 seconds
Is there any way to make these warnings go away?
Restarting the kernel works, but IPython's %reset and %clear aren't enough to fix it, either.
python python-import pytest
asked Jan 2 at 15:58
endolithendolith
11k1884157
add a comment |
I created some unit tests and run them from the same file. For tests in the same file:
if __name__ == "__main__":
import pytest
pytest.main(['--tb=short', __file__])
For tests in another file:
if __name__ == '__main__':
import pytest
pytest.main(['./test_stuff.py', "--capture=sys"])
In either case, when I execute the file the first time, it works fine, but the second and subsequent times it gives a bunch of warnings:
============================== warnings summary ===============================
C:Anaconda3libsite-packages_pytestconfig__init__.py:754
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_remotedata
self._mark_plugins_for_rewrite(hook)
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_openfiles
self._mark_plugins_for_rewrite(hook)
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_doctestplus
self._mark_plugins_for_rewrite(hook)
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_arraydiff
self._mark_plugins_for_rewrite(hook)
-- Docs: https://docs.pytest.org/en/latest/warnings.html
==================== 1 passed, 4 warnings in 0.06 seconds
Is there any way to make these warnings go away?
Restarting the kernel works, but IPython's %reset and %clear aren't enough to fix it, either.
python python-import pytest
asked Jan 2 at 15:58
endolithendolith
11k1884157
I created some unit tests and run them from the same file. For tests in the same file:
if __name__ == "__main__":
import pytest
pytest.main(['--tb=short', __file__])
For tests in another file:
if __name__ == '__main__':
import pytest
pytest.main(['./test_stuff.py', "--capture=sys"])
In either case, when I execute the file the first time, it works fine, but the second and subsequent times it gives a bunch of warnings:
============================== warnings summary ===============================
C:Anaconda3libsite-packages_pytestconfig__init__.py:754
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_remotedata
self._mark_plugins_for_rewrite(hook)
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_openfiles
self._mark_plugins_for_rewrite(hook)
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_doctestplus
self._mark_plugins_for_rewrite(hook)
C:Anaconda3libsite-packages_pytestconfig__init__.py:754: PytestWarning: Module already imported so cannot be rewritten: pytest_arraydiff
self._mark_plugins_for_rewrite(hook)
-- Docs: https://docs.pytest.org/en/latest/warnings.html
==================== 1 passed, 4 warnings in 0.06 seconds
Is there any way to make these warnings go away?
Restarting the kernel works, but IPython's %reset and %clear aren't enough to fix it, either.
python python-import pytest
python python-import pytest
asked Jan 2 at 15:58
endolithendolith
11k1884157
asked Jan 2 at 15:58
endolithendolith
11k1884157
edited Jan 2 at 16:04
endolith
asked Jan 2 at 15:58
endolithendolith
11k1884157
asked Jan 2 at 15:58
endolithendolith
11k1884157
asked Jan 2 at 15:58
endolithendolith
11k1884157
11k1884157
add a comment |
add a comment |
3 Answers
3
active
oldest
votes
Use subprocess instead of pytest.main:
if __name__ == "__main__":
import subprocess
subprocess.call(['pytest', '--tb=short', str(__file__)])
If the above does not print anything, try the workaround (as suggested in comments):
if __name__ == "__main__":
from subprocess import Popen, PIPE
with Popen(['pytest',
'--tb=short', # shorter traceback format
str(__file__)], stdout=PIPE, bufsize=1,
universal_newlines=True) as p:
for line in p.stdout:
print(line, end='')
answered Feb 13 at 9:07
mrkwjcmrkwjc
330311
This doesn't print the output at all, though... :/
– endolith
Feb 19 at 3:09
It does. :) At least in Spyder IDE with ipython console (Python 3.7). Also direct call from command line and repeated calls from inside ipython do print anything you like... Maybe you catch somewhere else your sdtout and stderr?
– mrkwjc
Feb 19 at 8:08
No it doesn't print anything in Spyder. This works though: github.com/pytest-dev/pytest/issues/3143#issuecomment-464973797
– endolith
Feb 19 at 14:50
1
Well, my configuration differs only in pytest. I have version 4.2.0. Neverthless i edited the answer to cover the no printing case.
– mrkwjc
Feb 20 at 22:31
1
I just tested things on Windows and subprocessed pytest really does not print output. It seems this is Windows specific problem.
– mrkwjc
Feb 22 at 21:37
|
show 4 more comments
It would appear that pytest just isn't really designed to perform pytest.main() calls repeatedly from within the same process. The pytest documentation mentions:
Calling pytest.main() will result in importing your tests and any
modules that they import. Due to the caching mechanism of python’s
import system, making subsequent calls to pytest.main() from the same
process will not reflect changes to those files between the calls. For
this reason, making multiple calls to pytest.main() from the same
process (in order to re-run tests, for example) is not recommended.
So actually the real danger of performing multiple pytest.main() calls within the same process is that you could get false-positive or false-negative test results if you've edited your code files inbetween.
The Spyder IDE has a nifty feature though that seems to negate this issue: the User Module Reloader (UMR). If enabled, then any changed user modules are automatically reloaded when a script file is (re-)run.
Therefore I think that as long as you're working in Spyder (with the UMR feature enabled!), you can safely rerun pytest.main() without the need for a new console. The pytest module already-imported warnings you can then simply suppress, since those pytest modules will not have changed. This can be done with pytest's -W flag. Example:
if __name__ == '__main__':
import pytest
pytest.main(['./test_stuff.py', "--capture=sys", "-W", "ignore:Module already imported:pytest.PytestWarning"])
answered Jan 2 at 19:14
XukraoXukrao
2,4632930
1
It didn't used to have this problem. Is there a recommended way to run tests every time a file is edited and run?
– endolith
Jan 2 at 22:49
1
@endolith My own recommendation would be to use to an IDE that supports custom run configurations. Within the IDE set up a dedicated run configuration for your pytest tests (one that always launches a new process).
– Xukrao
Jan 3 at 15:33
1
@endolith "Execute in dedicated console" results in a new console (i.e. new process) being started upon first run of the code file, but not upon subsequent reruns of the same code file. "Remove all variables" results in only user-defined variables being removed. Try using the run configuration options as described in the edited answer instead.
– Xukrao
Jan 4 at 19:40
1
@endolith "evert time I edit it, I Run it and it says whether the tests still pass." This surprised me at first. I was expecting that subsequent test runs would be giving false-positive or false-negative results (due to edited code files not being reloaded). However after discovering and reading about Spyder's User Module Reloader (UMR) it's starting to make sense. This UMR ensures that previously imported user modules are automatically reloaded if they've been changed (quite a useful feature).
– Xukrao
Jan 4 at 23:23
1
@endolith I think this means that as long as you're working in Spyder, you can actually safely rerunpytest.main()without the need for a new console. The warnings that you were getting you can simply suppress (see edited answer).
– Xukrao
Jan 4 at 23:24
|
show 5 more comments
If you are only concerned about warnings, you can use --disable-warnings argument. You can also filter out only the warnings you are getting now with --pythonwarnings=PYTHONWARNINGS argument in pytest.main . pytest --help has more info about these arguments.
It seems that you are invoking pytest with ipython or jupyter. python.main imports pytest specific modules at the time of pytest initialization. When you run pytest.main again, it throws the warnings. There are two possible ways to reload pytest to avoid getting this initialization warnings.
You can either use pytest.exit after pytest.main or reload pytest after pytest.main .
Let us know if these approaches work.
answered Jan 3 at 0:11
SilentGuySilentGuy
17016
Be careful. While these solutions will indeed get rid of the pytest warnings, one larger issue remains: the user's to-be-tested code files are not reloaded each time, so any changes made to the code files are ignored during subsequent pytest runs.
– Xukrao
Jan 3 at 16:04
exit and reload don't work :/
– endolith
Jan 4 at 4:54
--disable-warningsworks, but--pythonwarnings=PYTHONWARNINGSsaysINTERNALERROR> File "C:Anaconda3libwarnings.py", line 236, in _getaction INTERNALERROR> raise _OptionError("invalid action: %r" % (action,)) INTERNALERROR> warnings._OptionError: invalid action: 'PYTHONWARNINGS'
– endolith
Jan 5 at 21:00
Correct syntax to hide particular warning in this case (taken from an answer here): pytest.main(['./test_stuff.py', "--capture=sys", "--pythonwarnings", "ignore:Module already imported:pytest.PytestWarning"]) You should look into reloading pytest module as that will be the cleanest solution in your case.
– SilentGuy
Jan 7 at 20:11
add a comment |
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3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
Use subprocess instead of pytest.main:
if __name__ == "__main__":
import subprocess
subprocess.call(['pytest', '--tb=short', str(__file__)])
If the above does not print anything, try the workaround (as suggested in comments):
if __name__ == "__main__":
from subprocess import Popen, PIPE
with Popen(['pytest',
'--tb=short', # shorter traceback format
str(__file__)], stdout=PIPE, bufsize=1,
universal_newlines=True) as p:
for line in p.stdout:
print(line, end='')
answered Feb 13 at 9:07
mrkwjcmrkwjc
330311
This doesn't print the output at all, though... :/
– endolith
Feb 19 at 3:09
It does. :) At least in Spyder IDE with ipython console (Python 3.7). Also direct call from command line and repeated calls from inside ipython do print anything you like... Maybe you catch somewhere else your sdtout and stderr?
– mrkwjc
Feb 19 at 8:08
No it doesn't print anything in Spyder. This works though: github.com/pytest-dev/pytest/issues/3143#issuecomment-464973797
– endolith
Feb 19 at 14:50
1
Well, my configuration differs only in pytest. I have version 4.2.0. Neverthless i edited the answer to cover the no printing case.
– mrkwjc
Feb 20 at 22:31
1
I just tested things on Windows and subprocessed pytest really does not print output. It seems this is Windows specific problem.
– mrkwjc
Feb 22 at 21:37
|
show 4 more comments
Use subprocess instead of pytest.main:
if __name__ == "__main__":
import subprocess
subprocess.call(['pytest', '--tb=short', str(__file__)])
If the above does not print anything, try the workaround (as suggested in comments):
if __name__ == "__main__":
from subprocess import Popen, PIPE
with Popen(['pytest',
'--tb=short', # shorter traceback format
str(__file__)], stdout=PIPE, bufsize=1,
universal_newlines=True) as p:
for line in p.stdout:
print(line, end='')
answered Feb 13 at 9:07
mrkwjcmrkwjc
330311
This doesn't print the output at all, though... :/
– endolith
Feb 19 at 3:09
It does. :) At least in Spyder IDE with ipython console (Python 3.7). Also direct call from command line and repeated calls from inside ipython do print anything you like... Maybe you catch somewhere else your sdtout and stderr?
– mrkwjc
Feb 19 at 8:08
No it doesn't print anything in Spyder. This works though: github.com/pytest-dev/pytest/issues/3143#issuecomment-464973797
– endolith
Feb 19 at 14:50
1
Well, my configuration differs only in pytest. I have version 4.2.0. Neverthless i edited the answer to cover the no printing case.
– mrkwjc
Feb 20 at 22:31
1
I just tested things on Windows and subprocessed pytest really does not print output. It seems this is Windows specific problem.
– mrkwjc
Feb 22 at 21:37
|
show 4 more comments
Use subprocess instead of pytest.main:
if __name__ == "__main__":
import subprocess
subprocess.call(['pytest', '--tb=short', str(__file__)])
If the above does not print anything, try the workaround (as suggested in comments):
if __name__ == "__main__":
from subprocess import Popen, PIPE
with Popen(['pytest',
'--tb=short', # shorter traceback format
str(__file__)], stdout=PIPE, bufsize=1,
universal_newlines=True) as p:
for line in p.stdout:
print(line, end='')
answered Feb 13 at 9:07
mrkwjcmrkwjc
330311
Use subprocess instead of pytest.main:
if __name__ == "__main__":
import subprocess
subprocess.call(['pytest', '--tb=short', str(__file__)])
If the above does not print anything, try the workaround (as suggested in comments):
if __name__ == "__main__":
from subprocess import Popen, PIPE
with Popen(['pytest',
'--tb=short', # shorter traceback format
str(__file__)], stdout=PIPE, bufsize=1,
universal_newlines=True) as p:
for line in p.stdout:
print(line, end='')
answered Feb 13 at 9:07
mrkwjcmrkwjc
330311
edited Feb 20 at 22:32
answered Feb 13 at 9:07
mrkwjcmrkwjc
330311
answered Feb 13 at 9:07
mrkwjcmrkwjc
330311
answered Feb 13 at 9:07
mrkwjcmrkwjc
330311
330311
This doesn't print the output at all, though... :/
– endolith
Feb 19 at 3:09
It does. :) At least in Spyder IDE with ipython console (Python 3.7). Also direct call from command line and repeated calls from inside ipython do print anything you like... Maybe you catch somewhere else your sdtout and stderr?
– mrkwjc
Feb 19 at 8:08
No it doesn't print anything in Spyder. This works though: github.com/pytest-dev/pytest/issues/3143#issuecomment-464973797
– endolith
Feb 19 at 14:50
1
Well, my configuration differs only in pytest. I have version 4.2.0. Neverthless i edited the answer to cover the no printing case.
– mrkwjc
Feb 20 at 22:31
1
I just tested things on Windows and subprocessed pytest really does not print output. It seems this is Windows specific problem.
– mrkwjc
Feb 22 at 21:37
|
show 4 more comments
This doesn't print the output at all, though... :/
– endolith
Feb 19 at 3:09
It does. :) At least in Spyder IDE with ipython console (Python 3.7). Also direct call from command line and repeated calls from inside ipython do print anything you like... Maybe you catch somewhere else your sdtout and stderr?
– mrkwjc
Feb 19 at 8:08
No it doesn't print anything in Spyder. This works though: github.com/pytest-dev/pytest/issues/3143#issuecomment-464973797
– endolith
Feb 19 at 14:50
1
Well, my configuration differs only in pytest. I have version 4.2.0. Neverthless i edited the answer to cover the no printing case.
– mrkwjc
Feb 20 at 22:31
1
I just tested things on Windows and subprocessed pytest really does not print output. It seems this is Windows specific problem.
– mrkwjc
Feb 22 at 21:37
This doesn't print the output at all, though... :/
– endolith
Feb 19 at 3:09
This doesn't print the output at all, though... :/
– endolith
Feb 19 at 3:09
It does. :) At least in Spyder IDE with ipython console (Python 3.7). Also direct call from command line and repeated calls from inside ipython do print anything you like... Maybe you catch somewhere else your sdtout and stderr?
– mrkwjc
Feb 19 at 8:08
It does. :) At least in Spyder IDE with ipython console (Python 3.7). Also direct call from command line and repeated calls from inside ipython do print anything you like... Maybe you catch somewhere else your sdtout and stderr?
– mrkwjc
Feb 19 at 8:08
No it doesn't print anything in Spyder. This works though: github.com/pytest-dev/pytest/issues/3143#issuecomment-464973797
– endolith
Feb 19 at 14:50
No it doesn't print anything in Spyder. This works though: github.com/pytest-dev/pytest/issues/3143#issuecomment-464973797
– endolith
Feb 19 at 14:50
1
1
Well, my configuration differs only in pytest. I have version 4.2.0. Neverthless i edited the answer to cover the no printing case.
– mrkwjc
Feb 20 at 22:31
Well, my configuration differs only in pytest. I have version 4.2.0. Neverthless i edited the answer to cover the no printing case.
– mrkwjc
Feb 20 at 22:31
1
1
I just tested things on Windows and subprocessed pytest really does not print output. It seems this is Windows specific problem.
– mrkwjc
Feb 22 at 21:37
I just tested things on Windows and subprocessed pytest really does not print output. It seems this is Windows specific problem.
– mrkwjc
Feb 22 at 21:37
|
show 4 more comments
It would appear that pytest just isn't really designed to perform pytest.main() calls repeatedly from within the same process. The pytest documentation mentions:
Calling pytest.main() will result in importing your tests and any
modules that they import. Due to the caching mechanism of python’s
import system, making subsequent calls to pytest.main() from the same
process will not reflect changes to those files between the calls. For
this reason, making multiple calls to pytest.main() from the same
process (in order to re-run tests, for example) is not recommended.
So actually the real danger of performing multiple pytest.main() calls within the same process is that you could get false-positive or false-negative test results if you've edited your code files inbetween.
The Spyder IDE has a nifty feature though that seems to negate this issue: the User Module Reloader (UMR). If enabled, then any changed user modules are automatically reloaded when a script file is (re-)run.
Therefore I think that as long as you're working in Spyder (with the UMR feature enabled!), you can safely rerun pytest.main() without the need for a new console. The pytest module already-imported warnings you can then simply suppress, since those pytest modules will not have changed. This can be done with pytest's -W flag. Example:
if __name__ == '__main__':
import pytest
pytest.main(['./test_stuff.py', "--capture=sys", "-W", "ignore:Module already imported:pytest.PytestWarning"])
answered Jan 2 at 19:14
XukraoXukrao
2,4632930
1
It didn't used to have this problem. Is there a recommended way to run tests every time a file is edited and run?
– endolith
Jan 2 at 22:49
1
@endolith My own recommendation would be to use to an IDE that supports custom run configurations. Within the IDE set up a dedicated run configuration for your pytest tests (one that always launches a new process).
– Xukrao
Jan 3 at 15:33
1
@endolith "Execute in dedicated console" results in a new console (i.e. new process) being started upon first run of the code file, but not upon subsequent reruns of the same code file. "Remove all variables" results in only user-defined variables being removed. Try using the run configuration options as described in the edited answer instead.
– Xukrao
Jan 4 at 19:40
1
@endolith "evert time I edit it, I Run it and it says whether the tests still pass." This surprised me at first. I was expecting that subsequent test runs would be giving false-positive or false-negative results (due to edited code files not being reloaded). However after discovering and reading about Spyder's User Module Reloader (UMR) it's starting to make sense. This UMR ensures that previously imported user modules are automatically reloaded if they've been changed (quite a useful feature).
– Xukrao
Jan 4 at 23:23
1
@endolith I think this means that as long as you're working in Spyder, you can actually safely rerunpytest.main()without the need for a new console. The warnings that you were getting you can simply suppress (see edited answer).
– Xukrao
Jan 4 at 23:24
|
show 5 more comments
It would appear that pytest just isn't really designed to perform pytest.main() calls repeatedly from within the same process. The pytest documentation mentions:
Calling pytest.main() will result in importing your tests and any
modules that they import. Due to the caching mechanism of python’s
import system, making subsequent calls to pytest.main() from the same
process will not reflect changes to those files between the calls. For
this reason, making multiple calls to pytest.main() from the same
process (in order to re-run tests, for example) is not recommended.
So actually the real danger of performing multiple pytest.main() calls within the same process is that you could get false-positive or false-negative test results if you've edited your code files inbetween.
The Spyder IDE has a nifty feature though that seems to negate this issue: the User Module Reloader (UMR). If enabled, then any changed user modules are automatically reloaded when a script file is (re-)run.
Therefore I think that as long as you're working in Spyder (with the UMR feature enabled!), you can safely rerun pytest.main() without the need for a new console. The pytest module already-imported warnings you can then simply suppress, since those pytest modules will not have changed. This can be done with pytest's -W flag. Example:
if __name__ == '__main__':
import pytest
pytest.main(['./test_stuff.py', "--capture=sys", "-W", "ignore:Module already imported:pytest.PytestWarning"])
answered Jan 2 at 19:14
XukraoXukrao
2,4632930
1
It didn't used to have this problem. Is there a recommended way to run tests every time a file is edited and run?
– endolith
Jan 2 at 22:49
1
@endolith My own recommendation would be to use to an IDE that supports custom run configurations. Within the IDE set up a dedicated run configuration for your pytest tests (one that always launches a new process).
– Xukrao
Jan 3 at 15:33
1
@endolith "Execute in dedicated console" results in a new console (i.e. new process) being started upon first run of the code file, but not upon subsequent reruns of the same code file. "Remove all variables" results in only user-defined variables being removed. Try using the run configuration options as described in the edited answer instead.
– Xukrao
Jan 4 at 19:40
1
@endolith "evert time I edit it, I Run it and it says whether the tests still pass." This surprised me at first. I was expecting that subsequent test runs would be giving false-positive or false-negative results (due to edited code files not being reloaded). However after discovering and reading about Spyder's User Module Reloader (UMR) it's starting to make sense. This UMR ensures that previously imported user modules are automatically reloaded if they've been changed (quite a useful feature).
– Xukrao
Jan 4 at 23:23
1
@endolith I think this means that as long as you're working in Spyder, you can actually safely rerunpytest.main()without the need for a new console. The warnings that you were getting you can simply suppress (see edited answer).
– Xukrao
Jan 4 at 23:24
|
show 5 more comments
It would appear that pytest just isn't really designed to perform pytest.main() calls repeatedly from within the same process. The pytest documentation mentions:
Calling pytest.main() will result in importing your tests and any
modules that they import. Due to the caching mechanism of python’s
import system, making subsequent calls to pytest.main() from the same
process will not reflect changes to those files between the calls. For
this reason, making multiple calls to pytest.main() from the same
process (in order to re-run tests, for example) is not recommended.
So actually the real danger of performing multiple pytest.main() calls within the same process is that you could get false-positive or false-negative test results if you've edited your code files inbetween.
The Spyder IDE has a nifty feature though that seems to negate this issue: the User Module Reloader (UMR). If enabled, then any changed user modules are automatically reloaded when a script file is (re-)run.
Therefore I think that as long as you're working in Spyder (with the UMR feature enabled!), you can safely rerun pytest.main() without the need for a new console. The pytest module already-imported warnings you can then simply suppress, since those pytest modules will not have changed. This can be done with pytest's -W flag. Example:
if __name__ == '__main__':
import pytest
pytest.main(['./test_stuff.py', "--capture=sys", "-W", "ignore:Module already imported:pytest.PytestWarning"])
answered Jan 2 at 19:14
XukraoXukrao
2,4632930
It would appear that pytest just isn't really designed to perform pytest.main() calls repeatedly from within the same process. The pytest documentation mentions:
Calling pytest.main() will result in importing your tests and any
modules that they import. Due to the caching mechanism of python’s
import system, making subsequent calls to pytest.main() from the same
process will not reflect changes to those files between the calls. For
this reason, making multiple calls to pytest.main() from the same
process (in order to re-run tests, for example) is not recommended.
So actually the real danger of performing multiple pytest.main() calls within the same process is that you could get false-positive or false-negative test results if you've edited your code files inbetween.
The Spyder IDE has a nifty feature though that seems to negate this issue: the User Module Reloader (UMR). If enabled, then any changed user modules are automatically reloaded when a script file is (re-)run.
Therefore I think that as long as you're working in Spyder (with the UMR feature enabled!), you can safely rerun pytest.main() without the need for a new console. The pytest module already-imported warnings you can then simply suppress, since those pytest modules will not have changed. This can be done with pytest's -W flag. Example:
if __name__ == '__main__':
import pytest
pytest.main(['./test_stuff.py', "--capture=sys", "-W", "ignore:Module already imported:pytest.PytestWarning"])
answered Jan 2 at 19:14
XukraoXukrao
2,4632930
edited Jan 5 at 0:05
answered Jan 2 at 19:14
XukraoXukrao
2,4632930
answered Jan 2 at 19:14
XukraoXukrao
2,4632930
answered Jan 2 at 19:14
XukraoXukrao
2,4632930
2,4632930
1
It didn't used to have this problem. Is there a recommended way to run tests every time a file is edited and run?
– endolith
Jan 2 at 22:49
1
@endolith My own recommendation would be to use to an IDE that supports custom run configurations. Within the IDE set up a dedicated run configuration for your pytest tests (one that always launches a new process).
– Xukrao
Jan 3 at 15:33
1
@endolith "Execute in dedicated console" results in a new console (i.e. new process) being started upon first run of the code file, but not upon subsequent reruns of the same code file. "Remove all variables" results in only user-defined variables being removed. Try using the run configuration options as described in the edited answer instead.
– Xukrao
Jan 4 at 19:40
1
@endolith "evert time I edit it, I Run it and it says whether the tests still pass." This surprised me at first. I was expecting that subsequent test runs would be giving false-positive or false-negative results (due to edited code files not being reloaded). However after discovering and reading about Spyder's User Module Reloader (UMR) it's starting to make sense. This UMR ensures that previously imported user modules are automatically reloaded if they've been changed (quite a useful feature).
– Xukrao
Jan 4 at 23:23
1
@endolith I think this means that as long as you're working in Spyder, you can actually safely rerunpytest.main()without the need for a new console. The warnings that you were getting you can simply suppress (see edited answer).
– Xukrao
Jan 4 at 23:24
|
show 5 more comments
1
It didn't used to have this problem. Is there a recommended way to run tests every time a file is edited and run?
– endolith
Jan 2 at 22:49
1
@endolith My own recommendation would be to use to an IDE that supports custom run configurations. Within the IDE set up a dedicated run configuration for your pytest tests (one that always launches a new process).
– Xukrao
Jan 3 at 15:33
1
@endolith "Execute in dedicated console" results in a new console (i.e. new process) being started upon first run of the code file, but not upon subsequent reruns of the same code file. "Remove all variables" results in only user-defined variables being removed. Try using the run configuration options as described in the edited answer instead.
– Xukrao
Jan 4 at 19:40
1
@endolith "evert time I edit it, I Run it and it says whether the tests still pass." This surprised me at first. I was expecting that subsequent test runs would be giving false-positive or false-negative results (due to edited code files not being reloaded). However after discovering and reading about Spyder's User Module Reloader (UMR) it's starting to make sense. This UMR ensures that previously imported user modules are automatically reloaded if they've been changed (quite a useful feature).
– Xukrao
Jan 4 at 23:23
1
@endolith I think this means that as long as you're working in Spyder, you can actually safely rerunpytest.main()without the need for a new console. The warnings that you were getting you can simply suppress (see edited answer).
– Xukrao
Jan 4 at 23:24
1
1
It didn't used to have this problem. Is there a recommended way to run tests every time a file is edited and run?
– endolith
Jan 2 at 22:49
It didn't used to have this problem. Is there a recommended way to run tests every time a file is edited and run?
– endolith
Jan 2 at 22:49
1
1
@endolith My own recommendation would be to use to an IDE that supports custom run configurations. Within the IDE set up a dedicated run configuration for your pytest tests (one that always launches a new process).
– Xukrao
Jan 3 at 15:33
@endolith My own recommendation would be to use to an IDE that supports custom run configurations. Within the IDE set up a dedicated run configuration for your pytest tests (one that always launches a new process).
– Xukrao
Jan 3 at 15:33
1
1
@endolith "Execute in dedicated console" results in a new console (i.e. new process) being started upon first run of the code file, but not upon subsequent reruns of the same code file. "Remove all variables" results in only user-defined variables being removed. Try using the run configuration options as described in the edited answer instead.
– Xukrao
Jan 4 at 19:40
@endolith "Execute in dedicated console" results in a new console (i.e. new process) being started upon first run of the code file, but not upon subsequent reruns of the same code file. "Remove all variables" results in only user-defined variables being removed. Try using the run configuration options as described in the edited answer instead.
– Xukrao
Jan 4 at 19:40
1
1
@endolith "evert time I edit it, I Run it and it says whether the tests still pass." This surprised me at first. I was expecting that subsequent test runs would be giving false-positive or false-negative results (due to edited code files not being reloaded). However after discovering and reading about Spyder's User Module Reloader (UMR) it's starting to make sense. This UMR ensures that previously imported user modules are automatically reloaded if they've been changed (quite a useful feature).
– Xukrao
Jan 4 at 23:23
@endolith "evert time I edit it, I Run it and it says whether the tests still pass." This surprised me at first. I was expecting that subsequent test runs would be giving false-positive or false-negative results (due to edited code files not being reloaded). However after discovering and reading about Spyder's User Module Reloader (UMR) it's starting to make sense. This UMR ensures that previously imported user modules are automatically reloaded if they've been changed (quite a useful feature).
– Xukrao
Jan 4 at 23:23
1
1
@endolith I think this means that as long as you're working in Spyder, you can actually safely rerun
pytest.main() without the need for a new console. The warnings that you were getting you can simply suppress (see edited answer).– Xukrao
Jan 4 at 23:24
@endolith I think this means that as long as you're working in Spyder, you can actually safely rerun
pytest.main() without the need for a new console. The warnings that you were getting you can simply suppress (see edited answer).– Xukrao
Jan 4 at 23:24
|
show 5 more comments
If you are only concerned about warnings, you can use --disable-warnings argument. You can also filter out only the warnings you are getting now with --pythonwarnings=PYTHONWARNINGS argument in pytest.main . pytest --help has more info about these arguments.
It seems that you are invoking pytest with ipython or jupyter. python.main imports pytest specific modules at the time of pytest initialization. When you run pytest.main again, it throws the warnings. There are two possible ways to reload pytest to avoid getting this initialization warnings.
You can either use pytest.exit after pytest.main or reload pytest after pytest.main .
Let us know if these approaches work.
answered Jan 3 at 0:11
SilentGuySilentGuy
17016
Be careful. While these solutions will indeed get rid of the pytest warnings, one larger issue remains: the user's to-be-tested code files are not reloaded each time, so any changes made to the code files are ignored during subsequent pytest runs.
– Xukrao
Jan 3 at 16:04
exit and reload don't work :/
– endolith
Jan 4 at 4:54
--disable-warningsworks, but--pythonwarnings=PYTHONWARNINGSsaysINTERNALERROR> File "C:Anaconda3libwarnings.py", line 236, in _getaction INTERNALERROR> raise _OptionError("invalid action: %r" % (action,)) INTERNALERROR> warnings._OptionError: invalid action: 'PYTHONWARNINGS'
– endolith
Jan 5 at 21:00
Correct syntax to hide particular warning in this case (taken from an answer here): pytest.main(['./test_stuff.py', "--capture=sys", "--pythonwarnings", "ignore:Module already imported:pytest.PytestWarning"]) You should look into reloading pytest module as that will be the cleanest solution in your case.
– SilentGuy
Jan 7 at 20:11
add a comment |
If you are only concerned about warnings, you can use --disable-warnings argument. You can also filter out only the warnings you are getting now with --pythonwarnings=PYTHONWARNINGS argument in pytest.main . pytest --help has more info about these arguments.
It seems that you are invoking pytest with ipython or jupyter. python.main imports pytest specific modules at the time of pytest initialization. When you run pytest.main again, it throws the warnings. There are two possible ways to reload pytest to avoid getting this initialization warnings.
You can either use pytest.exit after pytest.main or reload pytest after pytest.main .
Let us know if these approaches work.
answered Jan 3 at 0:11
SilentGuySilentGuy
17016
Be careful. While these solutions will indeed get rid of the pytest warnings, one larger issue remains: the user's to-be-tested code files are not reloaded each time, so any changes made to the code files are ignored during subsequent pytest runs.
– Xukrao
Jan 3 at 16:04
exit and reload don't work :/
– endolith
Jan 4 at 4:54
--disable-warningsworks, but--pythonwarnings=PYTHONWARNINGSsaysINTERNALERROR> File "C:Anaconda3libwarnings.py", line 236, in _getaction INTERNALERROR> raise _OptionError("invalid action: %r" % (action,)) INTERNALERROR> warnings._OptionError: invalid action: 'PYTHONWARNINGS'
– endolith
Jan 5 at 21:00
Correct syntax to hide particular warning in this case (taken from an answer here): pytest.main(['./test_stuff.py', "--capture=sys", "--pythonwarnings", "ignore:Module already imported:pytest.PytestWarning"]) You should look into reloading pytest module as that will be the cleanest solution in your case.
– SilentGuy
Jan 7 at 20:11
add a comment |
If you are only concerned about warnings, you can use --disable-warnings argument. You can also filter out only the warnings you are getting now with --pythonwarnings=PYTHONWARNINGS argument in pytest.main . pytest --help has more info about these arguments.
It seems that you are invoking pytest with ipython or jupyter. python.main imports pytest specific modules at the time of pytest initialization. When you run pytest.main again, it throws the warnings. There are two possible ways to reload pytest to avoid getting this initialization warnings.
You can either use pytest.exit after pytest.main or reload pytest after pytest.main .
Let us know if these approaches work.
answered Jan 3 at 0:11
SilentGuySilentGuy
17016
If you are only concerned about warnings, you can use --disable-warnings argument. You can also filter out only the warnings you are getting now with --pythonwarnings=PYTHONWARNINGS argument in pytest.main . pytest --help has more info about these arguments.
It seems that you are invoking pytest with ipython or jupyter. python.main imports pytest specific modules at the time of pytest initialization. When you run pytest.main again, it throws the warnings. There are two possible ways to reload pytest to avoid getting this initialization warnings.
You can either use pytest.exit after pytest.main or reload pytest after pytest.main .
Let us know if these approaches work.
answered Jan 3 at 0:11
SilentGuySilentGuy
17016
answered Jan 3 at 0:11
SilentGuySilentGuy
17016
answered Jan 3 at 0:11
SilentGuySilentGuy
17016
answered Jan 3 at 0:11
SilentGuySilentGuy
17016
17016
Be careful. While these solutions will indeed get rid of the pytest warnings, one larger issue remains: the user's to-be-tested code files are not reloaded each time, so any changes made to the code files are ignored during subsequent pytest runs.
– Xukrao
Jan 3 at 16:04
exit and reload don't work :/
– endolith
Jan 4 at 4:54
--disable-warningsworks, but--pythonwarnings=PYTHONWARNINGSsaysINTERNALERROR> File "C:Anaconda3libwarnings.py", line 236, in _getaction INTERNALERROR> raise _OptionError("invalid action: %r" % (action,)) INTERNALERROR> warnings._OptionError: invalid action: 'PYTHONWARNINGS'
– endolith
Jan 5 at 21:00
Correct syntax to hide particular warning in this case (taken from an answer here): pytest.main(['./test_stuff.py', "--capture=sys", "--pythonwarnings", "ignore:Module already imported:pytest.PytestWarning"]) You should look into reloading pytest module as that will be the cleanest solution in your case.
– SilentGuy
Jan 7 at 20:11
add a comment |
Be careful. While these solutions will indeed get rid of the pytest warnings, one larger issue remains: the user's to-be-tested code files are not reloaded each time, so any changes made to the code files are ignored during subsequent pytest runs.
– Xukrao
Jan 3 at 16:04
exit and reload don't work :/
– endolith
Jan 4 at 4:54
--disable-warningsworks, but--pythonwarnings=PYTHONWARNINGSsaysINTERNALERROR> File "C:Anaconda3libwarnings.py", line 236, in _getaction INTERNALERROR> raise _OptionError("invalid action: %r" % (action,)) INTERNALERROR> warnings._OptionError: invalid action: 'PYTHONWARNINGS'
– endolith
Jan 5 at 21:00
Correct syntax to hide particular warning in this case (taken from an answer here): pytest.main(['./test_stuff.py', "--capture=sys", "--pythonwarnings", "ignore:Module already imported:pytest.PytestWarning"]) You should look into reloading pytest module as that will be the cleanest solution in your case.
– SilentGuy
Jan 7 at 20:11
Be careful. While these solutions will indeed get rid of the pytest warnings, one larger issue remains: the user's to-be-tested code files are not reloaded each time, so any changes made to the code files are ignored during subsequent pytest runs.
– Xukrao
Jan 3 at 16:04
Be careful. While these solutions will indeed get rid of the pytest warnings, one larger issue remains: the user's to-be-tested code files are not reloaded each time, so any changes made to the code files are ignored during subsequent pytest runs.
– Xukrao
Jan 3 at 16:04
exit and reload don't work :/
– endolith
Jan 4 at 4:54
exit and reload don't work :/
– endolith
Jan 4 at 4:54
--disable-warnings works, but --pythonwarnings=PYTHONWARNINGS says INTERNALERROR> File "C:Anaconda3libwarnings.py", line 236, in _getaction INTERNALERROR> raise _OptionError("invalid action: %r" % (action,)) INTERNALERROR> warnings._OptionError: invalid action: 'PYTHONWARNINGS'– endolith
Jan 5 at 21:00
--disable-warnings works, but --pythonwarnings=PYTHONWARNINGS says INTERNALERROR> File "C:Anaconda3libwarnings.py", line 236, in _getaction INTERNALERROR> raise _OptionError("invalid action: %r" % (action,)) INTERNALERROR> warnings._OptionError: invalid action: 'PYTHONWARNINGS'– endolith
Jan 5 at 21:00
Correct syntax to hide particular warning in this case (taken from an answer here): pytest.main(['./test_stuff.py', "--capture=sys", "--pythonwarnings", "ignore:Module already imported:pytest.PytestWarning"]) You should look into reloading pytest module as that will be the cleanest solution in your case.
– SilentGuy
Jan 7 at 20:11
Correct syntax to hide particular warning in this case (taken from an answer here): pytest.main(['./test_stuff.py', "--capture=sys", "--pythonwarnings", "ignore:Module already imported:pytest.PytestWarning"]) You should look into reloading pytest module as that will be the cleanest solution in your case.
– SilentGuy
Jan 7 at 20:11
add a comment |
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